T-101: Exact certificates of 77 catalogue packings: s(n) ≤ S', 1.2e-16 to 9.8e-15 above each side

V3 C3 Upper bound confirmed

2026-10-05 published · Daniel after Couzo, de Winter, Ellsworth, Levy · 77 cases, n=28 to 300

For each of 77 counts n from 28 to 300, s(n) <= S', where S' is the side of an exact rational packing Daniel published on 5 October 2026: this register's own known-best packing at that count, the one the Kingbird catalogue prints, solved to a nearby exact point of minimizing the side. The counts are 28, 37, 39, 41, 50, 51, 53 to 55, 69 to 71, 83, 87, 88, 101, 104, 107 to 109, 122, 124, 125, 127 to 129, 145 to 151, 153, 170, 171, 173 to 176, 178, 179, 197, 198, 200 to 205, 226, 227, 229 to 235, 257, 258, 260 to 262, 264 to 267, 290, 291, 293 to 296 and 298 to 300.

Each S' lies 1.2e-16 to 9.8e-15 above the side the catalogue prints, and each case record carries S' rounded up at the fourteen decimals printed as its verified upper bound, from 5.82444461667406 at n=28 to 17.82412338847855 at n=300.

Before this the verified upper bound was the integer grid at 74 of the counts, above the printed side by up to 0.464 at n=101, 122, 145, 170, 197, 226, 257, 290 and 291, and at n=69, 83 and 87 the rounded-up sides of exact certificates of a binary64 parse of the catalogue's pictures (T-088, T-089), 2e-14 to 8.9e-13 above it. At the 22 counts whose printed side is a decimal alone, the verified upper bound now agrees with the report to one unit of its last place.

At the other 55 the catalogue also gives the side as a closed form, and S' lies 7.6e-20 to 1.8e-19 above it, the certificate's outward rounding, so the verified upper bound trails the report by one unit of the fourteenth decimal. Forty-nine of those closed forms are irrational, which no rational certificate reaches; the other six, at n=50, 171, 198, 230, 261 and 293, are rational, and an exact certificate of the packing at that side would reach them; at n=50 a rational one appears to exist.

Every certificate is decided here exactly: converted without rounding, by sqpack's exact separating-axis test and by devtools.check_rational_witness_independent, which share no code with each other or with the source, so independently re-implemented. The source's own checkers, verify_cert.py and verify_cert2.py, run here as retained, accept every one as well, reproduced with the producer's code. All four refuse each certificate with its tightest pair moved one unit of the side's denominator past its separating-axis gap, and each with its box shrunk that unit past its least clearance.

Matched square for square with the known-best witness, every pose lies within 7.1e-4 of it, and every square the source does not list as free within 1.2e-7; four of the 77 were solved from the witness after the source's unpublished local squeeze (n=127, 129, 260 and 299). The source's report that 75 of the exact points are KKT local minima rests on numerical checks and is not verified here; it bears on the packings, not on s(n).

Daniel after the catalogue's finders and Ellsworth's analytic minimisation, evand/square-packing, from this register's witnesses. On jlevy/squares#375 the author offered these certificates as an independent exact replay of the existing upper bounds and asked for nothing to be registered from them; the owner decided on 6 October 2026 to act on them where they lower a verified ceiling. The author says the solver, its checkers and the batch were written with Claude (Anthropic) as a coding and research agent, directed and reviewed by him.

Significance, composition and next rung
Significance
Seventy-seven verified ceilings moved onto packings the record already reported, off the integer grid at 74 counts by up to 0.464, and to within one unit of the report's last place at 22: citable details of each case that move no reported side and no theorem, S2 as T-098's certificate of n=126, which took that count's ceiling off the grid the same way. No new packing and no reusable technique here; the exact solver is the source's, as in T-098.
Composition
Two machine entries decide all 77 bounds, each at its case's verified value: the exact decision here by two checkers of this repository that share no code with each other or the source (exact-algebraic, independently re-implemented), and the source's own two checkers run here (exact-algebraic, reproduced with the producer's code). Both are exact rational decisions of the same certificates, one method, so C3 with one machine method beside it. Each case record's verified value is S' rounded up at the printed precision, which s(n) <= S' implies. The comparisons with the printed sides, the closed forms and the witnesses' poses are recorded values and set no rung, and the source's numerical KKT reports are outside the claim.
Next rung
V4 and C4 need two adversarial AI reviews of the complete claim by distinct reviewers and a human oversight record. A method-distinct second route, such as an interval decision of each certificate's pose, would be shown beside the rung. No certificate here has yet been decided by code of a reviewer's own. At the 49 counts whose report is an irrational closed form, the verified upper bound reaches the report only through an exact algebraic certificate of the packing at that side. At the six rational ones, n=50, 171, 198, 230, 261 and 293, an exact certificate at that side would reach it, rational where the packing's exact point is; at n=50 the source's own exact point, before its outward rounding, appears to be a rational one (the review's EC-1, think-l8gt). This entry gives neither.
Novelty
previously-published Present in an identified source

The cases

This result concerns 77 cases, too many to draw one by one. Each is listed with the film’s bounds, the proved lower bound and the best known side, and links to its case record, where its packing and number line are drawn.

nProved lowerBest knownGapStatusRecords
285.7350005.8244450.08944461…open=Rfrontier n-028.md
376.4400006.5986200.15861960…open=frontier n-037.md
396.6500006.8107230.16072208…frontier n-039.md
416.7750006.9266940.15169309…frontier n-041.md
507.4000007.5714290.17142857…frontier n-050.md
517.4700007.6903560.22035593…frontier n-051.md
537.6275007.8228760.19537565…frontier n-053.md
547.6850007.8466680.16166719…frontier n-054.md
557.7280007.9457720.21777100…open≈frontier n-055.md
698.6200008.8271950.20719465…open=frontier n-069.md
708.6575008.8809610.22346037…frontier n-070.md
718.7210008.9440720.22307155…open≈frontier n-071.md
839.3700009.6347580.26475764…open=frontier n-083.md
879.5800009.8388160.25881526…frontier n-087.md
889.6200009.8824520.26245103…frontier n-088.md
10110.28000010.5355340.25553390…frontier n-101.md
10410.7071070.42710678…frontier n-104.md
10710.36154110.8466680.48512573…frontier n-107.md
10810.62000010.9048220.28482101…frontier n-108.md
10910.46242910.9497480.48731804…frontier n-109.md
12211.04751111.5355340.48802235…frontier n-122.md
12411.14189811.6568550.51495592…frontier n-124.md
12511.18877911.7071070.51832761…frontier n-125.md
12711.28192911.8108790.52894946…frontier n-127.md
12811.32820311.8250920.49688805…frontier n-128.md
12911.37428111.8700140.49573226…frontier n-129.md
14512.04339612.5355340.49213752…frontier n-145.md
14612.08663012.5837830.49715196…frontier n-146.md
14712.12970312.6568550.52715089…frontier n-147.md
14812.1726170.48423671…frontier n-148.md
14912.21537412.7071070.49173226…frontier n-149.md
15012.25797612.7781750.52019857…frontier n-150.md
15112.30042312.8228760.52245193…frontier n-151.md
15312.38486412.8700140.48514952…frontier n-153.md
17013.03993613.5355340.49559770…frontier n-170.md
17113.07974513.5714290.49168294…frontier n-171.md
17313.15898813.6568550.49786534…frontier n-173.md
17413.19842513.7071070.50868168…frontier n-174.md
17513.23773913.7641750.52643511…frontier n-175.md
17613.27693213.7958730.51893997…frontier n-176.md
17813.35496013.8466680.49170706…frontier n-178.md
17913.39379613.8837960.48999853…frontier n-179.md
19714.03698614.5355340.49854753…frontier n-197.md
19814.07387114.5714290.49755661…frontier n-198.md
20014.14734414.6568550.50951018…frontier n-200.md
20114.18393214.7071070.52317459…frontier n-201.md
20214.22042214.7279230.50749932…frontier n-202.md
20314.25681614.7781750.52135810…frontier n-203.md
20414.29311414.8086430.51552861…frontier n-204.md
20514.32931614.8244520.49513446…frontier n-205.md
22615.03444115.5355340.50109205…frontier n-226.md
22715.06880215.5636260.49482336…frontier n-227.md
22915.13728115.6501620.51288034…frontier n-229.md
23015.17140015.6829270.51152607…frontier n-230.md
23115.20544115.7071070.50166561…frontier n-231.md
23215.23940215.7641750.52477134…frontier n-232.md
23315.27328615.7781750.50488789…frontier n-233.md
23415.30709215.8228760.51578276…frontier n-234.md
23515.34082215.8266060.48578355…frontier n-235.md
25716.03222416.5355340.50330933…frontier n-257.md
25816.06438216.5634490.49906558…frontier n-258.md
26016.12849916.6457540.51725364…frontier n-260.md
26116.16045916.6787800.51832011…frontier n-261.md
26216.19235416.7071070.51475195…frontier n-262.md
26416.25595116.7747360.51878387…frontier n-264.md
26516.28765316.7781750.49052118…frontier n-265.md
26616.31929216.8230290.50373673…frontier n-266.md
26716.35086716.8388160.48794778…frontier n-267.md
29017.03027517.5355340.50525865…frontier n-290.md
29117.0604950.47503874…frontier n-291.md
29317.12077017.6341470.51337620…frontier n-293.md
29417.15082517.6568550.50602844…frontier n-294.md
29517.18082717.7042330.52340547…frontier n-295.md
29617.21077417.7071070.49633181…frontier n-296.md
29817.27050917.7781750.50766476…frontier n-298.md
29917.30029717.8228760.52257803…frontier n-299.md
30017.33003217.8241240.49409070…frontier n-300.md

Results on these cases

84 results in the register on these cases, oldest first
  1. 2005 published T-007 · 77 of these cases

    s(n)≥min(⌈n⌉,n−2⌊n⌋+1+1) for 4≤n≤324

    Lower bound incomplete on these cases, superseded by T-048, T-069, T-073, T-075, T-080, T-082, T-083, T-090, T-091, T-107, T-110, T-111, T-180 (reported) and T-216

    Nagamochi · Nagamochi 2005 · source · register

  2. 2018 published T-087 · case 37

    s(37)≥53/2+22−1 and s(61)≥73/2+22−1, by optimal piercing

    Lower bound reviewed superseded by T-069

    Bašić, Slivková · Basic-Slivkova 2018 · source · register

  3. 2026-09-04 published T-085 · 77 of these cases

    Nagamochi 2005, Lemma 1 is false for every container with a>3 and b>2

    Correction confirmed

    Karakuş; Vlasenko · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register

  4. 2026-09-22 published T-044 · 8 of these cases

    Weighted point lower bounds for ten counts in n=26…72, plus seven from the same files

    Lower bound confirmed superseded by T-082, T-090, T-091, T-110 and T-111

    Hosono after Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point bounds 2026 · packet · source · review · register

  5. 2026-09-22 published T-047 · case 28

    s(11)≥381/100; s(n)≥1377/250 for n=26…28; s(n)≥571/100 for n=29…31

    Lower bound confirmed superseded by T-107

    Tokoharu after Levy, Hosono, Stromquist, Nagamochi, Burns, Massaccesi · Tokoharu density 2026 · packet · source · review · register

  6. 2026-09-24 published T-088 · case 69

    s(69)≤8.82719465572975, Ellsworth's degree-38 packing, certified exactly from its picture

    Upper bound confirmed superseded by T-101 and T-155

    Ellsworth after hmbelvedere, Cantrell, Schadt, Morandi · Ellsworth n69 2026-09-24 · packet · packet · register

  7. 2026-09-24 published T-089 · cases 83, 87

    s(83)≤9.63475764863195 and s(87)≤9.83881526994915, Chang's packings, certified exactly

    Upper bound confirmed superseded by T-101 and T-155

    Chang, Ellsworth after Cantrell, Hajba, Stenlund, Bidwell; Chang after Ellsworth, Cantrell, Schadt, Hajba, DeVincentis · Chang n83 2026-09-24 · Chang n87 2026-09-24 · packet · packet · register

  8. 2026-09-27 published T-045 · case 28

    Rectangle-density lower bounds replayed at 15 counts in n=18…78

    Lower bound confirmed superseded by T-107

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · packet · packet · source · review · register

  9. 2026-09-27 published T-046 · 12 of these cases

    Rectangle-density lower bounds reported for 48 counts in n=18…95

    Lower bound recorded superseded by T-069, T-082, T-090, T-091, T-107, T-110 and T-111

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · wand125 rectangle bounds 2026-09-28 · packet · packet · register

  10. 2026-09-28 published T-048 · cases 50, 51

    s(50)≥37/5=7.4

    Lower bound confirmed

    Hosono after Daniel, Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point and mixed bounds 2026-09-28 · packet · source · review · register

  11. 2026-09-28 published T-070 · 9 of these cases

    Rectangle-density lower bounds replayed at 25 counts in n=29…95

    Lower bound confirmed superseded by T-082, T-090, T-091, T-110 and T-111

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · register

  12. 2026-09-29 published T-058 · 15 of these cases

    Rectangle-certificate ceiling α·UB(n) proved for n=1..100; B·UB(n) on 64 grid rows

    Method limit confirmed

    Hosono after Tokoharu, Daniel · wand125 tools 2026 · packet · register

  13. 2026-09-29 published T-083 · 77 of these cases

    s(n)≥1/2+n−⌊n⌋+1/4 for every nonsquare 8≤n≤324

    Lower bound confirmed

    Karakuş · Karakuş 2026 · source · register

  14. 2026-10-01 published T-068 · 10 of these cases

    Rectangle-density lower bounds verified at 34 counts in n=19…95

    Lower bound confirmed on these cases, superseded by T-082, T-090, T-091, T-107, T-110 and T-111

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · source · review · register

  15. 2026-10-01 published T-069 · case 37

    Mixed rectangle-measure lower bounds replayed at n=37,65,66,90,92

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-01 · packet · source · review · register

  16. 2026-10-01 published T-074 · 9 of these cases

    Rectangle-density lower bounds replayed at 31 counts in n=19…95

    Lower bound confirmed on these cases, superseded by T-082, T-090, T-091, T-107, T-110 and T-111

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · packet · source · review · register

  17. 2026-10-02 published T-071 · case 87

    Mixed rectangle-measure lower bounds replayed at n=84…87

    Lower bound confirmed superseded by T-091

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-02 · packet · source · review · register

  18. 2026-10-02 published T-073 · cases 83, 101, 104

    Linear-measure lower bounds replayed at n=83 and n=101…105

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear certificates 2026-10-02 · packet · source · review · register

  19. 2026-10-02 published T-075 · cases 83, 87, 88

    Mixed rectangle-measure lower bounds replayed at nine counts in n=83…96

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds afternoon 2026-10-02 · packet · source 1 · source 2 · review · register

  20. 2026-10-02 published T-077 · case 70

    Rectangle-density lower bounds replayed at n=20, 42 and 70

    Lower bound confirmed superseded by T-091

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-02 · packet · packet · source 1 · source 2 · review 1 · review 2 · register

  21. 2026-10-02 published T-080 · cases 101, 104

    Linear-measure lower bound replayed at n=101…105

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear certificates 2026-10-02 · packet · source · review · register

  22. 2026-10-03 published T-082 · 7 of these cases

    Mixed rectangle-measure lower bounds verified at 22 counts in n=51…96

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-03 · packet · packet · source · review · register

  23. 2026-10-04 published T-090 · cases 51, 69, 88

    Mixed rectangle-measure lower bounds verified at 17 counts in n=42…96

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-04 · packet · source · review · register

  24. 2026-10-04 published T-091 · 6 of these cases

    Mixed rectangle-measure lower bounds verified at 17 counts in n=53…95

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds evening 2026-10-04 · packet · source · review · register

  25. 2026-10-05 published T-101 this result · 77 of these cases

    Exact certificates of 77 catalogue packings: s(n) ≤ S', 1.2e-16 to 9.8e-15 above each side

    Upper bound confirmed

    Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register

  26. 2026-10-06 published T-107 · case 28

    Mixed rectangle-measure lower bound verified at n=28, on a declared net

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds check2 2026-10-06 · packet · source · review · register

  27. 2026-10-06 published T-110 · case 39

    Mixed rectangle-measure lower bound verified at n=39, on a declared net

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds check2 2026-10-06 · packet · source · review · register

  28. 2026-10-06 published T-111 · case 41

    Mixed rectangle-measure lower bound verified at n=41, on a declared net

    Lower bound confirmed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds check2 2026-10-06 · packet · source · review · register

  29. 2026-10-07 published T-113 · cases 108, 129

    s(n)≤Sn at ten counts, n=108 to 303, from new SQUISH rational packings

    Upper bound confirmed superseded by T-174 and T-186

    Chaoweeraprasit after Ellsworth · SQUISH ten packings 2026-10-07 · packet · register

  30. 2026-10-07 published T-114 · case 153

    s(153)≤7250614903299225/562949953421312, from a SQUISH rational packing

    Upper bound confirmed superseded by T-173

    Chaoweeraprasit after Ellsworth · SQUISH n153 2026-10-07 · packet · packet · register

  31. 2026-10-07 published T-115 · cases 129, 179, 258

    s(n)≤Sn at twelve counts, from the SQUISH update’s new and smaller rational packings

    Upper bound confirmed superseded by T-146, T-174 and T-186

    Chaoweeraprasit after Couzo and Ellsworth · SQUISH update 2026-10-07 · packet · register

  32. 2026-10-07 published T-116 · cases 88, 108, 179

    s(n)≤Sn at nine counts, from the second SQUISH update’s new rational packings

    Upper bound confirmed superseded by T-127 and T-174

    Chaoweeraprasit after Ellsworth, Couzo and SQUISH · SQUISH second update 2026-10-07 · packet · register

  33. 2026-10-07 published T-119 · case 266

    Three exact feasible upper bounds at n=266,270,272 from new source arrangements

    Upper bound confirmed

    Daniel after Levy, Ellsworth, Couzo, Stead · Daniel new arrangements 2026-10-07 · packet · register

  34. 2026-10-07 published T-124 · case 28

    Reported non-strict local minima for 178 source configurations

    Restricted optimality recorded

    Daniel after Couzo · Daniel exact and local reports 2026 · packet · register

  35. 2026-10-08 published T-125 · 14 of these cases

    Complete rational construction reports at 25 counts

    Upper bound confirmed superseded by T-126, T-127, T-134, T-146, T-173, T-174, T-186 and T-187

    Xu · ry-xu square packing 2026 · packet · register

  36. 2026-10-08 published T-126 · case 51

    Undilated n51 construction over Q(sqrt2)

    Upper bound confirmed

    Xu · ry-xu square packing 2026 · packet · register

  37. 2026-10-08 published T-127 · 5 of these cases

    Fourteen rational refinements, seventeen complete source cases

    Upper bound confirmed

    Gupta after Chaoweeraprasit, Daniel · Gupta rational refinements 2026-10-08 · packet · register

  38. 2026-10-08 published T-128 · cases 108, 127

    Eight complete rational refinements from Couzo

    Upper bound confirmed superseded by T-174

    Couzo after Xu, Chaoweeraprasit, Gupta, Ellsworth, Daniel, Levy · Couzo exact refinements 2026-10-08 · packet · register

  39. 2026-10-08 published T-130 · case 175

    Five follow-up rational refinements from Couzo

    Upper bound confirmed superseded by T-186

    Couzo after Xu, Daniel, Ellsworth, Levy · Couzo follow-up refinements 2026-10-08 · packet · register

  40. 2026-10-09 published T-134 · case 267

    Six exact rational certificates from Couzo

    Upper bound confirmed

    Couzo after Polkovskyi, Chaoweeraprasit, Gupta, Xu, Daniel, Ellsworth, Levy · Couzo exact certificates 2026-10-09 · packet · register

  41. 2026-10-09 published T-136 · cases 153, 232

    Seventeen exact rational packings from SQUISH's third request

    Upper bound confirmed on these cases, superseded by T-173 and T-186

    Chaoweeraprasit after Couzo, Xu, Göbel, Schadt, Ellsworth, Hajba, Levy · SQUISH third request 2026-10-09 · packet · register

  42. 2026-10-09 published T-138 · 5 of these cases

    Exact witnesses at Mishapolk's printed ceilings, the smallest known at 103 and 258 when registered

    Upper bound confirmed superseded by T-134, T-146, T-174 and T-186

    Polkovskyi after Stenlund, Friedman, Ellsworth, Chaoweeraprasit, Couzo, Xu, Levy · Mishapolk decimal poses 2026-10-09 · packet · register

  43. 2026-10-10 published T-137 · case 70

    An exact rational refinement of Xu's packing of 70 squares

    Upper bound confirmed superseded by T-146

    Deleeuw after Xu, Levy · Deleeuw n70 refinement 2026-10-10 · packet · register

  44. 2026-10-10 published T-140 · case 175

    Six more exact rational certificates from Couzo

    Upper bound confirmed superseded by T-186

    Couzo after Chaoweeraprasit, Polkovskyi, Xu, Daniel, Ellsworth, Levy · Couzo certificates 2026-10-10 · packet · register

  45. 2026-10-10 published T-142 · case 28

    Mixed rectangle-measure lower bound s(28)≥2297/400 reported, on a 2,073-direction declared net

    Lower bound recorded

    Hosono after Tokoharu and Levy · wand125 fine-net n28 n30 2026-10-10 · packet · register

  46. 2026-10-10 published T-144 · cases 122, 124, 125

    Linear-measure lower bound s(n)≥563/50=11.26 for n=122…126, reported

    Lower bound recorded

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear n122 2026-10-10 · packet · register

  47. 2026-10-10 published T-146 · 6 of these cases

    Exact rational certificates at fifteen counts from Daniel's regularized record lists

    Upper bound confirmed

    Daniel after Xu, Chaoweeraprasit, Polkovskyi, Levy · Daniel regularized lists 2026-10-10 · packet · register

  48. 2026-10-11 published T-148 · case 153

    A packing of 153 squares built from Xu's packing of 70, its contacts reclosed at a new angle

    Upper bound confirmed superseded by T-173

    PingYou Ltd after Xu, Daniel, Levy · PingYou n153 certificate 2026-10-11 · packet · register

  49. 2026-10-11 published T-150 · cases 146, 261

    Exact rational refinements of Xu's packings of 146 and 261 squares

    Upper bound confirmed superseded by T-174 and T-187

    Barnett after Xu, Daniel, Levy · Barnett refinements 2026-10-11 · packet · register

  50. 2026-10-11 published T-151 · case 176

    Nine exact rational packings from SQUISH's fourth request

    Upper bound confirmed superseded by T-186

    Chaoweeraprasit after Couzo, Gupta, Ellsworth, Friedman, Levy · SQUISH fourth request 2026-10-11 · packet · register

  51. 2026-10-11 published T-185 · case 175

    A tighter packing of 175 squares from Couzo, superseded by Ostashev's composition

    Upper bound confirmed superseded by T-186

    Couzo after Xu, Daniel, Ellsworth, Levy · Couzo n175 2026-10-11 · packet · register

  52. 2026-10-12 established T-155 · 58 of these cases

    Exact regularized sides at 59 counts, 5.4e-20 to 9.9e-15 below the ceilings they replace

    Upper bound confirmed

    Levy after Daniel · register

  53. 2026-10-12 published T-158 · cases 175, 232, 264

    New packings of 175, 232 and 264 squares built on a new 38-square rectangle, each certified exactly

    Upper bound confirmed superseded by T-186

    Ostashev after Nakajima, Ellsworth, Schadt, Friedman, de Winter, Daniel, Levy, Xu · Ostashev records 2026-10-12 · packet · register

  54. 2026-10-12 published T-161 · case 176

    Exact rational certificates at 156, 176, 237 and 271 from Couzo

    Upper bound confirmed superseded by T-186

    Couzo after Ostashev, Chaoweeraprasit, Fang, Daniel, Ellsworth, Levy · Couzo certificates 2026-10-12 · packet · register

  55. 2026-10-12 published T-162 · cases 129, 204

    New packings of 129, 204 and 303 squares, a cut-out and two compositions, each certified exactly

    Upper bound confirmed superseded by T-186 and T-225

    Ostashev after Nakajima, Chaoweeraprasit, Daniel, Xu, Levy · Ostashev compositions 2026-10-12 · packet · register

  56. 2026-10-12 published T-165 · case 176

    A tighter certificate at 176 from Couzo, published with no issue

    Upper bound confirmed superseded by T-186

    Couzo after Daniel, Ostashev, BuddenPing, Fang, Ellsworth, Levy · Couzo certificates 2026-10-13 · packet · register

  57. 2026-10-12 published T-166 · case 153

    A tighter rational realization of PingYou Ltd's packing of 153 squares

    Upper bound confirmed superseded by T-173

    PingYou Ltd after Xu, Daniel, Levy · PingYou n153 refinement 2026-10-12 · packet · register

  58. 2026-10-12 published T-168 · case 146

    A further exact refinement of Xu's packing of 146 squares, after Barnett's

    Upper bound confirmed superseded by T-187

    PingYou Ltd after Xu, Barnett, Daniel, Levy · PingYou n146 refinement 2026-10-12 · packet · register

  59. 2026-10-12 published T-169 · case 261

    A further exact refinement of Xu's packing of 261 squares, after Barnett's

    Upper bound confirmed superseded by T-174

    PingYou Ltd after Xu, Barnett, Daniel, Levy · PingYou n261 refinement 2026-10-12 · packet · register

  60. 2026-10-12 published T-173 · case 153

    Polkovskyi's packings of 153 and 207 squares, each below the earlier refinements there

    Upper bound confirmed

    Polkovskyi after Xu, Chaoweeraprasit, Levy · Mishapolk exact certificates 2026-10-12 · packet · register

  61. 2026-10-13 established T-156 · case 290

    s(290)≤17.5355339059327376…, by monotonicity from T-155, with its own exact certificate

    Upper bound confirmed

    Levy after Daniel · register

  62. 2026-10-13 published T-174 · 18 of these cases

    Tighter certificates at 68 counts from PingYou Ltd, of others' packings and its own

    Upper bound confirmed

    PingYou Ltd after Friedman, Ellsworth, Daniel, Xu, Barnett, Couzo, Ostashev, Chaoweeraprasit, Gupta, Fang, Polkovskyi, Levy · PingYou PR 574 certificates 2026-10-13 · packet · register

  63. 2026-10-13 published T-176 · case 39

    Mixed rectangle-measure lower bound s(39)≥533/80 reported, on a 2,073-direction declared net

    Lower bound reviewed

    Hosono after Tokoharu and Levy · wand125 fine-net n37 n39 n44 2026-10-13 · packet · register

  64. 2026-10-13 published T-178 · case 37

    Mixed rectangle-measure lower bound s(37)≥2599/400 reported, on a 2,073-direction declared net

    Lower bound reviewed

    Hosono after Tokoharu and Levy · wand125 fine-net n37 n39 n44 2026-10-13 · packet · register

  65. 2026-10-13 published T-179 · 5 of these cases

    Linear-measure lower bound s(n)≥306/25=12.24 for n=145…149, reported

    Lower bound reviewed

    Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 linear n145 2026-10-13 · packet · register

  66. 2026-10-13 published T-180 · 73 of these cases

    Closed-form lower bound s(N)≥a(N) for every non-square N≥49, reported

    Lower bound reviewed

    Hosono · wand125 closed form 2026-10-14 · packet · packet · register

  67. 2026-10-14 published T-186 · 6 of these cases

    Exact certificates at twelve counts from Polkovskyi, tightening the smallest reported there

    Upper bound confirmed

    Polkovskyi after Ostashev, Couzo, PingYou Ltd, Levy · Mishapolk KKT refinements 2026-10-14 · packet · register

  68. 2026-10-14 published T-187 · case 146

    A smaller packing of 146 squares from Daniel's chain search, started from Xu's packing

    Upper bound confirmed

    Daniel after Xu · Daniel n146 2026-10-14 · packet · register

  69. 2026-10-15 published T-192 · case 28

    Continuous-pose lower bound s(28)>1149/200 reported, by two of the source's programs

    Lower bound recorded

    Hosono after Guzhou0806, Tokoharu, Levy · wand125 continuous n28 2026-10-15 · packet · register

  70. 2026-10-16 published T-193 · 8 of these cases

    Exact algebraic sides at sixteen counts from Daniel, of packings the record credits

    Upper bound confirmed

    Daniel after Xu, Chaoweeraprasit, Ostashev, Couzo, PingYou Ltd, Gupta, Polkovskyi, Levy · Daniel exact current records 2026-10-16 · packet · register

  71. 2026-10-16 published T-202 · case 41

    Mixed rectangle-measure lower bound s(41)≥2721/400 reported, on a 2,073-direction declared net

    Lower bound recorded

    Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register

  72. 2026-10-16 published T-204 · case 51

    Mixed rectangle-measure lower bound s(51)≥3011/400 reported, on a 2,073-direction declared net

    Lower bound recorded

    Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register

  73. 2026-10-16 published T-209 · case 88

    Mixed rectangle-measure lower bound s(88)≥3853/400 reported, on the 201-direction net

    Lower bound recorded

    Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register

  74. 2026-10-16 published T-215 · case 107

    Mixed rectangle-measure lower bound s(107)≥529/50 reported, on the 201-direction net

    Lower bound recorded

    Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register

  75. 2026-10-16 published T-216 · case 108

    Mixed rectangle-measure lower bound s(108)≥531/50 verified, on the 201-direction net

    Lower bound confirmed

    Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · source · review · register

  76. 2026-10-17 published T-196 · cases 227, 229, 260

    de Winter reports three smaller rational upper bounds at 227, 229 and 260

    Upper bound confirmed superseded by T-225

    de Winter after Levy · de Winter upper bounds 2026-10-17 · packet · register

  77. 2026-10-17 published T-198 · case 229

    Daniel's opening n229 dilation certificate, after Couzo and de Winter

    Upper bound confirmed superseded by T-225

    Daniel after Couzo, de Winter, Levy · Daniel n229 dilation 2026-10-17 · packet · register

  78. 2026-10-17 published T-226 · case 204

    Couzo's 204 of #670, below Polkovskyi's T-186, since superseded by his own #675 and #678

    Upper bound recorded superseded by T-225

    Couzo after Polkovskyi, Daniel, Levy · Couzo issue 670 2026-10-17 · packet · packet · register

  79. 2026-10-17 published T-227 · cases 227, 229

    Couzo's refinements of de Winter's 227 and 229, below T-196 at both

    Upper bound recorded superseded by T-225

    Couzo after de Winter, Daniel, Levy · Couzo issue 672 2026-10-17 · packet · packet · register

  80. 2026-10-18 published T-199 · case 229

    Daniel's smaller n229 update, replacing the opening certificate

    Upper bound confirmed superseded by T-225

    Daniel after Couzo, de Winter, Levy · Daniel n229 dilation update 2026-10-18 · packet · register

  81. 2026-10-18 published T-223 · cases 204, 260

    Couzo's smaller packings at 204 and 260, the two in the corpus of issue 678's 85 bounds

    Upper bound confirmed superseded by T-225

    Couzo after de Winter, Polkovskyi, Daniel, Fang, PingYou Ltd, Levy · Couzo issue 678 2026-10-18 · packet · register

  82. 2026-10-18 published T-228 · case 204

    Couzo's 204 of #675, below his #670, since superseded by his #678

    Upper bound recorded superseded by T-225

    Couzo after Polkovskyi, Daniel, Levy · Couzo issue 675 2026-10-18 · packet · packet · register

  83. 2026-10-20 published T-225 · cases 204, 227, 229, 260

    Daniel's solved, regularized views at 204, 227, 229 and 260, each the smallest side reported there

    Upper bound confirmed

    Daniel after Couzo, de Winter, Polkovskyi, Levy · Daniel regularized lists 2026-10-20 · packet · register

  84. 2026-10-22 published T-229 · case 204

    Polkovskyi's re-solves of the house packings at 105 and 204, below T-174 and T-225

    Upper bound recorded

    Polkovskyi after Couzo, Muglich, Daniel, Xu, PingYou Ltd, Levy · Mishapolk issue 719 2026-10-22 · packet · register