T-113: s(n)≤Sn at ten counts, n=108 to 303, from new SQUISH rational packings

V3 C3 Upper bound confirmed superseded by T-139, T-174, T-186, T-197 and T-222

2026-10-07 published · Chaoweeraprasit after Ellsworth · 10 cases, n=108 to 303

Chaoweeraprasit (itsnaka), using SQUISH, establishes s(n) <= S_n for n=108, 126, 129,

130, 154, 155, 180, 209, 238 and 303 in the ten-packing release submitted on

jlevy/squares#401 on 7 October 2026. Each S_n is the exact rational side in the retained

packing facts, from about 0.0004126 to 0.0067047 below the earlier reported upper bound

here. Each certificate supplies rational centres and rational half-angle parameters for

closed unit squares in the rational container.

The claim establishes only upper bounds, with no optimality or rigidity conclusion. The

author credits Ellsworth’s records and tools and states human-directed Claude Opus 5.5

assistance.

This repository confirmed the upper bounds by independently re-implemented exact-rational

checks: sqpack.witness.exact_verify and devtools.check_rational_witness_independent accept

every pair and container wall of each certificate, with both geometric controls rejected.

Significance, composition and next rung
Significance
New packings reduce the recorded upper bounds at ten counts by about 0.0004 to 0.0067, substantive case-bound improvements. They settle no exact optimum and introduce no proved general packing theorem.
Composition
Each source rational triple is converted without rounding to exact unit-square corners, at the source’s unchanged rational side. Both native exact_verify and the independently written rational-corner checker decide every pair and wall; the source-to-witness conversion and complete scope are accepted by the retained mathematical review. The wrapper binds the receipt to the decided witness, checks the full roster and upward decimal display, and replays both geometric controls. This is an independently re-implemented confirmation, sharing no verification code with the producer; the two first-party routes share the converted corners, YAML and Python rational arithmetic.
Next rung
V4 and C4 need a retained human oversight record for the claim, certificate, assumptions, two deciding implementations, controls and accepted adversarial AI reviews. The two separately prompted project AI reviews are retained; human oversight is not. Rung 5 needs a proof-assistant formalization with the open replay and two human expert reviews. No local or global optimality claim is made by these upper-bound certificates.
Novelty
previously-published Present in an identified source

The cases

This result concerns 10 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
10810.62000010.9048220.28482101…open=frontier n-108.md
12611.23545511.7426410.50718541…frontier n-126.md
12911.37428111.8700140.49573226…frontier n-129.md
13011.42016411.9044840.48431819…frontier n-130.md
15412.42686012.9211010.49424049…frontier n-154.md
15512.46870912.9522610.48355174…frontier n-155.md
18013.43251713.9169940.48447636…frontier n-180.md
20914.47318814.9462240.47303461…frontier n-209.md
23815.44155215.9241070.48255398…frontier n-238.md
30317.41892417.9099590.49103397…frontier n-303.md

Results on these cases

34 results in the register on these cases, oldest first
  1. 2005 published T-007 · 10 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-083, T-180 (reported) and T-216

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085 · 10 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

  3. 2026-09-27 published T-056 · 7 of these cases

    Smaller packings for 49 counts from n=68 to 307, each certified two independent ways

    Upper bound confirmed superseded by T-174, T-186, T-197 and T-222

    Couzo · franciscouzo square-packing 2026-09-27 · packet · register

  4. 2026-09-29 published T-083 · 10 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

  5. 2026-10-03 published T-092 · cases 209, 303

    Smaller packings again at seven counts from n=208 to 306, each certified two independent ways

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

    Couzo · franciscouzo square-packing 2026-10-03 · packet · register

  6. 2026-10-05 published T-098 · 7 of these cases

    Exact optima of 48 known-best packings: s(n) ≤ S', 3.5e-13 to 5.0e-11 below each printed side

    Upper bound confirmed on these cases, superseded by T-139, T-174, T-186, T-197 and T-222

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

  7. 2026-10-05 published T-101 · cases 108, 129

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

    Upper bound confirmed on these cases, superseded by T-174 and T-186

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

  8. 2026-10-07 published T-113 this result · 10 of these cases

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

    Upper bound confirmed superseded by T-139, T-174, T-186, T-197 and T-222

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

  9. 2026-10-07 published T-115 · 5 of these cases

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

    Upper bound confirmed superseded by T-139, T-174, T-186, T-197 and T-222

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

  10. 2026-10-07 published T-116 · cases 108, 180

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

    Upper bound confirmed superseded by T-174

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

  11. 2026-10-07 published T-129 · case 130

    Three dated Daniel certificate reports with historical source custody

    Upper bound recorded superseded by T-174

    Daniel after Couzo, Levy · Daniel dated certificates 105 and 130 2026-10-07 · Daniel dated certificate 292 2026-10-07 · packet · packet · packet · register

  12. 2026-10-08 published T-125 · cases 108, 126, 129, 130

    Complete rational construction reports at 25 counts

    Upper bound confirmed superseded by T-139, T-174 and T-186

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

  13. 2026-10-08 published T-127 · 7 of these cases

    Fourteen rational refinements, seventeen complete source cases

    Upper bound confirmed on these cases, superseded by T-174, T-186 and T-222

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

  14. 2026-10-08 published T-128 · cases 108, 155, 180

    Eight complete rational refinements from Couzo

    Upper bound confirmed superseded by T-174 and T-197

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

  15. 2026-10-09 published T-134 · case 303

    Six exact rational certificates from Couzo

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

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

  16. 2026-10-09 published T-136 · cases 154, 209, 303

    Seventeen exact rational packings from SQUISH's third request

    Upper bound confirmed on these cases, superseded by T-174, T-186 and T-222

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

  17. 2026-10-09 published T-138 · cases 108, 180, 303

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

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

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

  18. 2026-10-09 published T-139 · case 126

    A more precise certificate of Xu's 126-square arrangement, from Daniel

    Upper bound confirmed

    Daniel after Xu, Chaoweeraprasit · Daniel trio126 2026-10-09 · packet · register

  19. 2026-10-10 published T-140 · case 209

    Six more exact rational certificates from Couzo

    Upper bound confirmed superseded by T-174

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

  20. 2026-10-10 published T-144 · case 126

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

    Lower bound recorded on these cases, superseded by T-180 (reported)

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

  21. 2026-10-10 published T-146 · cases 129, 303

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

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

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

  22. 2026-10-11 published T-149 · case 155

    New packings of 155, 156 and 211 squares, each with an exact rational certificate

    Upper bound confirmed superseded by T-197

    Ostashev after Nakajima, Levy, Xu · Ostashev records 2026-10-11 · packet · register

  23. 2026-10-11 published T-151 · case 238

    Nine exact rational packings from SQUISH's fourth request

    Upper bound confirmed superseded by T-174

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

  24. 2026-10-12 published T-160 · case 154

    A smaller packing of 154 squares from Daniel's size-chaining explorer, certified exactly

    Upper bound confirmed superseded by T-222

    Daniel after Couzo, Levy · Daniel n154 2026-10-12 · packet · register

  25. 2026-10-12 published T-162 · cases 129, 303

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

    Upper bound confirmed superseded by T-186

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

  26. 2026-10-12 published T-172 · case 154

    A packing of 154 squares from Couzo, continuing Daniel's arrangement

    Upper bound confirmed superseded by T-222

    Couzo after Daniel, Ostashev, Fang, Ellsworth, Levy · Couzo issue-583 certificates 2026-10-13 · packet · register

  27. 2026-10-13 published T-174 · 9 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

  28. 2026-10-13 published T-180 · 10 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

  29. 2026-10-13 published T-182 · case 154

    Exact rational certificates at 154, 211 and 241 from Couzo

    Upper bound confirmed on these cases, superseded by T-222

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

  30. 2026-10-14 published T-186 · cases 129, 154, 303

    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

  31. 2026-10-16 published T-193 · case 126

    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

  32. 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

  33. 2026-10-17 published T-197 · case 155

    Daniel's smaller n155 packing, started from Ostashev's packing

    Upper bound confirmed

    Daniel after Ostashev, Levy · Daniel n155 explorer 2026-10-17 · packet · register

  34. 2026-10-20 published T-222 · case 154

    Daniel's smaller n154 packing, continuing Couzo's #586 arrangement, certified exactly

    Upper bound confirmed

    Daniel after Couzo, Ostashev, Levy · Daniel n154 sweep 2026-10-20 · packet · packet · register