T-164: A packing of 302 squares from four boundary patches of Xu's packing of 70 and two upright banks

V3 C3 Upper bound confirmed superseded by T-186

2026-10-12 published · PingYou Ltd after Xu, Daniel, Levy · n=302

One complete rational source certificate reports a finite upper-bound improvement at the exact side it states: s(302)≤17.87027538273375975382555057.

All three retained jobs, the positive with its 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 derived fact to the pinned file it is derived from, fetched at the pin. No route here is the source's code; the source's runs of this repository's two maintained routes on its corners witnesses are its own and decide nothing here, so the replay is independently re-implemented. The 14 October review found no blocking defect.

The author reports that three exact checkers, its own rational polygon-projection checker and Daniel's unchanged verify_cert.py and verify_cert2.py, accept all 302 squares, 1,208 wall conditions and 45,451 pairs; that its package replays the recorded rational construction and checks the lossless conversion to its corners Witness/v2; and that this repository's sqpack exact_verify and check_rational_witness_independent, run unchanged, accept that witness. Those statements are the author's; no source program ran here.

Credit PingYou Ltd (https://github.com/BuddenPing/square-packing-certificates) with the n302 construction and its refinement, as the source asks: four boundary patches of Xu's n70 construction (ry-xu, issue 432), taken from Daniel's exact n70 certificate (the regularized n-070 certificate T-146 retains), with two upright banks of 105 and 147 squares. The source names Chaoweeraprasit's SQUISH n302 (issue 481) and Daniel's regularization of it (T-146) only as its comparison, and claims neither the n70 packing nor patch composition in general. The pinned source makes no statement about AI assistance; the author's statement of 12 October on issue 503 covers the n207 and n153 results only.

Measured pose by pose by that review, it is not the house's packing at 302, though 255 of its squares lie within a tenth of the house's under a reflection; that it holds four patches of Xu's n70 is the source's statement, consistent with the measurements and established by none of them. Couzo's issue 583 certificate (T-181), which continues this arrangement, is 2.62e-04 smaller and has held the case since 15 October 2026.

Significance, composition and next rung
Significance
A new arrangement at n=302, 1.75e-03 below the case ceiling, as T-147 and T-148 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

Case record
Regularized by the Squares Project with Daniel's regularizer (evand/square-packing, MIT)
As published
The packing as published, PingYou Ltd 2026 [Mishapolk KKT refinements 2026-10-14]

n=302

17.3817.870
171819
17.37818.378
nn+1

Proven

17.38934≤s(302)≤17.870014

  • exact

Citation record n-302

lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)

upperPingYou Ltd et al., GitHub (confirmed T-186)

Open

  • optimality

The case record

LowerUpper
Gap0.48066809…

Results on the case

15 results in the register on n=302, oldest first, each with what it established and how it stands now.

  1. 2005 published T-007

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

    V0 C1 Lower bound incomplete on this case, superseded by T-083 and T-180 (reported)

    Nagamochi · Nagamochi 2005 · source · register

  2. 2026-09-04 published T-085

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

    V3 C3 Correction confirmed

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

  3. 2026-09-27 published T-056

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

    V3 C3 Upper bound confirmed superseded by T-186

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

  4. 2026-09-29 published T-083

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

    V3 C3 Lower bound confirmed

    Karakuş · Karakuş 2026 · source · register

  5. 2026-10-05 published T-098

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

    V3 C3 Upper bound confirmed on this case, superseded by T-186

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

  6. 2026-10-07 published T-116

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

    V3 C3 Upper bound confirmed superseded by T-186

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

  7. 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-186

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

  8. 2026-10-09 published T-138

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

    V3 C3 Upper bound confirmed superseded by T-186

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

  9. 2026-10-10 published T-146

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

    V3 C3 Upper bound confirmed on this case, superseded by T-186

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

  10. 2026-10-12 published T-164 this result

    A packing of 302 squares from four boundary patches of Xu's packing of 70 and two upright banks

    V3 C3 Upper bound confirmed superseded by T-186

    PingYou Ltd after Xu, Daniel, Levy · PingYou n302 certificate 2026-10-12 · packet · register

  11. 2026-10-13 published T-174

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

    V3 C3 Upper bound confirmed on this case, superseded by T-186

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

  12. 2026-10-13 published T-180

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

    V0 C1 Lower bound reviewed

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

  13. 2026-10-13 published T-181

    Exact rational certificates at 211, 241 and 302 from Couzo

    V3 C3 Upper bound confirmed superseded by T-186

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

  14. 2026-10-14 published T-186

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

    V3 C3 Upper bound confirmed

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

  15. 2026-10-16 published T-193

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

    V3 C3 Upper bound confirmed

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