T-172: A packing of 154 squares from Couzo, continuing Daniel's arrangement
V3 C3 Upper bound confirmed superseded by T-222
One complete rational source certificate reports a finite upper-bound improvement at the exact side it states: .
All 21 retained jobs of the packet, its seven certificates with their duplicate-square and outside-container controls, were decided again here on 14 October 2026 by both maintained exact routes and equal their retained rows. A third exact route, half-extent containment and exact intersection area, decided the certificate with six controls each and held the retained file to its upstream bytes, fetched at the pin. No route here is the source's code; the author's runs of this repository's sqpack verifier are his and decide nothing here, so the replay is independently re-implemented. The 14 October review found no blocking defect.
Issue 570 names the certificate by its digest at a revision of franciscouzo/square-packing that GitHub no longer serves; the same bytes are certificates/n154.cert at the revision issue 583 pins, where the couzo-issue583-2026-10-13 packet retains them. The issue also reports , by a certificate in no reachable commit of the source, which is not retained and has no row here.
The author reports that the certificate passes this repository's sqpack verify.py and Daniel's verify_cert.py, at the revisions the issue names, in exact rational arithmetic; that statement is the author's. Both maintained exact routes accept it here and refuse its two controls.
Credit Couzo (https://github.com/franciscouzo/square-packing), continuing Daniel's arrangement of issue 552 (T-160) through the author's browser refinement, native basin hopping and exact finishing, with Daniel's exact contact solver. The author states that OpenAI Codex assisted the search and verification and that he directed the work.
Measured pose by pose by that review, it refines Daniel's packing (T-160) under a quarter turn, every square paired and none moved beyond 0.04. At 154 the same author's issue 586 (T-182) is smaller and has held the case since 15 October 2026.
Significance, composition and next rung
- Significance
- A refinement of Daniel's packing (T-160) to a new side 6.66e-05 below it, as T-152 and T-128 are; no lower bound or optimum.
- Next rung
- V4 and C4 need a second accepted adversarial review by a distinct reviewer and a retained human oversight record; one AI review, of 14 October, is retained.
- Novelty
- previously-published Present in an identified source
The case
As published
Proven
- exact
Citation record n-154
lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)
upperDaniel & Couzo, GitHub (confirmed T-222)
Open
- optimality
The case record
Results on the case
15 results in the register on , oldest first, each with what it established and how it stands now.
2005 published T-007
for
V0 C1 Lower bound incomplete on this case, superseded by T-083 and T-180 (reported)
2026-09-04 published T-085
Nagamochi 2005, Lemma 1 is false for every container with and
V3 C3 Correction confirmed
Karakuş; Vlasenko · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register
2026-09-27 published T-056
Smaller packings for 49 counts from to , each certified two independent ways
V3 C3 Upper bound confirmed superseded by T-222
Couzo · franciscouzo square-packing 2026-09-27 · packet · register
2026-09-29 published T-083
for every nonsquare
V3 C3 Lower bound confirmed
Karakuş · Karakuş 2026 · source · register
2026-10-05 published T-098
Exact optima of 48 known-best packings:
s(n) ≤ S',3.5e-13to5.0e-11below each printed sideV3 C3 Upper bound confirmed on this case, superseded by T-222
Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register
2026-10-07 published T-113
at ten counts, to 303, from new SQUISH rational packings
V3 C3 Upper bound confirmed superseded by T-222
Chaoweeraprasit after Ellsworth · SQUISH ten packings 2026-10-07 · packet · register
2026-10-07 published T-115
at twelve counts, from the SQUISH update’s new and smaller rational packings
V3 C3 Upper bound confirmed superseded by T-222
Chaoweeraprasit after Couzo and Ellsworth · SQUISH update 2026-10-07 · packet · register
2026-10-08 published T-127
Fourteen rational refinements, seventeen complete source cases
V3 C3 Upper bound confirmed on this case, superseded by T-222
Gupta after Chaoweeraprasit, Daniel · Gupta rational refinements 2026-10-08 · packet · register
2026-10-09 published T-136
Seventeen exact rational packings from SQUISH's third request
V3 C3 Upper bound confirmed on this case, superseded by T-222
Chaoweeraprasit after Couzo, Xu, Göbel, Schadt, Ellsworth, Hajba, Levy · SQUISH third request 2026-10-09 · packet · register
2026-10-12 published T-160
A smaller packing of 154 squares from Daniel's size-chaining explorer, certified exactly
V3 C3 Upper bound confirmed superseded by T-222
Daniel after Couzo, Levy · Daniel n154 2026-10-12 · packet · register
2026-10-12 published T-172 this result
A packing of 154 squares from Couzo, continuing Daniel's arrangement
V3 C3 Upper bound confirmed superseded by T-222
Couzo after Daniel, Ostashev, Fang, Ellsworth, Levy · Couzo issue-583 certificates 2026-10-13 · packet · register
2026-10-13 published T-180
Closed-form lower bound for every non-square , reported
V0 C1 Lower bound reviewed
Hosono · wand125 closed form 2026-10-14 · packet · packet · register
2026-10-13 published T-182
Exact rational certificates at 154, 211 and 241 from Couzo
V3 C3 Upper bound confirmed on this case, superseded by T-222
Couzo after Daniel, Ostashev, BuddenPing, Fang, Ellsworth, Levy · Couzo certificates 2026-10-13 · packet · register
2026-10-14 published T-186
Exact certificates at twelve counts from Polkovskyi, tightening the smallest reported there
V3 C3 Upper bound confirmed on this case, superseded by T-222
Polkovskyi after Ostashev, Couzo, PingYou Ltd, Levy · Mishapolk KKT refinements 2026-10-14 · packet · register
2026-10-20 published T-222
Daniel's smaller n154 packing, continuing Couzo's #586 arrangement, certified exactly
V3 C3 Upper bound confirmed
Daniel after Couzo, Ostashev, Levy · Daniel n154 sweep 2026-10-20 · packet · packet · register
Links
- On this site
- Case record, · Frontier row, · T-172 in the results table
On GitHub, at main
- Register
- T-172 in
results.yaml, line 21803 - Evidence
E-couzo-583-certificate-report·E-couzo-583-exact-feasibility- Proofs and certificates
- certificate
certificates - Sources
- Couzo issue-583 certificates 2026-10-13
- Source packet
resources/web/couzo-issue583-2026-10-13/README.md- Artifacts
8 artifacts and controls
resources/web/couzo-issue583-2026-10-13/README.mdresources/web/couzo-issue583-2026-10-13/acquisition/claims.jsonresources/web/couzo-issue583-2026-10-13/source/certificates/n154.certdevtools/upper_bound_reports.pydevtools/check_half_angle_area.pydocs/project/reviews/review-2026-10-14-upper-bound-imports-561-593.mdtests/test_upper_bound_reports.pytests/test_check_half_angle_area.py- Case file
frontier/n-154.md(verified lower, verified upper, reported lower, reported upper)