T-224: Daniel's smaller n270 packing, another arrangement found from Chaoweeraprasit's, certified exactly
V3 C3 Upper bound confirmed
One complete rational source certificate reports a finite upper-bound improvement at the exact side it states: .
The certificate and its duplicate-square and outside-container controls were decided here on 21 October 2026 by both maintained exact routes, and the frozen comparison rebuilt; no route here is the source's code, so the replay is independently re-implemented. The 21 October review found no blocking defect.
Issue 703 reports a packing found by Daniel's basin explorer in a near-record sweep over stored non-record descendants of Chaoweeraprasit's (itsnaka's) #500 packing (T-151), the register's packing, which PingYou Ltd refined in PR #574 (T-174); it asks that #500's packing be credited as the ultimate start, and calls this a new packing, a different local minimum from the register's. Measured here pose by pose, the packing is another arrangement of the design that the case's earlier house best packing (T-174) holds, not a refinement of it, found from #500's packing as the source describes.
The author reports that his two exact checkers, verify_cert.py (separating axes) and verify_cert2.py (polygon intersection), accept the certificate, and a KKT local minimum strict modulo 23 exact flat motions and not isolated, with 263 corner-corner contacts, no corner-corner MILP descent, 1 rattler and 67 tilted squares; those are numerical evidence at 80 digits, not proofs. The source's credits say the work was done with Claude (Anthropic) under Daniel's direction.
Significance, composition and next rung
- Significance
- Another arrangement of the design at 270, 3.47e-05 below the case and every report there, to a new KKT point with 15 squares moved beyond a tenth, two fewer tilted squares and no tilt angle shared; a smaller margin than #664's 271 (4.46e-05, three squares, S3) and #689's 308 (1.12e-03, S3), with as many squares beyond a tenth as the 308 (15), and well above T-188's 9.29e-06 (S2); no lower bound or optimum.
- Next rung
- None for the bound. V4 and C4 need a second accepted adversarial review by a distinct reviewer and a retained human oversight record; one AI review, of 21 October, is retained.
- Regularized drawings
- n = 270: a regularization of T-224’s packing by Levy (Daniel's search/regularize (MIT), evand/square-packing@675a5ea, conservative, coincide, through devtools.regularize_evand; unmodified; at its own side; 1 free square straightened; identity: measured here; nearest centres one to one; 24 squares moved, at most 0.13034; turns up to 0.217543°).
- Novelty
- previously-published Present in an identified source
The case
As published
Proven
- exact
Citation record n-270
lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)
upperDaniel 2026, GitHub (confirmed T-224)
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-224
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-224
Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register
2026-10-07 published T-119
Three exact feasible upper bounds at n=266,270,272 from new source arrangements
V3 C3 Upper bound confirmed on this case, superseded by T-224
Daniel after Levy, Ellsworth, Couzo, Stead · Daniel new arrangements 2026-10-07 · packet · register
2026-10-08 published T-130
Five follow-up rational refinements from Couzo
V3 C3 Upper bound confirmed superseded by T-224
Couzo after Xu, Daniel, Ellsworth, Levy · Couzo follow-up refinements 2026-10-08 · packet · register
2026-10-09 published T-134
Six exact rational certificates from Couzo
V3 C3 Upper bound confirmed on this case, superseded by T-224
Couzo after Polkovskyi, Chaoweeraprasit, Gupta, Xu, Daniel, Ellsworth, Levy · Couzo exact certificates 2026-10-09 · 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-224
Chaoweeraprasit after Couzo, Xu, Göbel, Schadt, Ellsworth, Hajba, Levy · SQUISH third request 2026-10-09 · packet · register
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-224
Polkovskyi after Stenlund, Friedman, Ellsworth, Chaoweeraprasit, Couzo, Xu, Levy · Mishapolk decimal poses 2026-10-09 · packet · register
2026-10-10 published T-140
Six more exact rational certificates from Couzo
V3 C3 Upper bound confirmed superseded by T-224
Couzo after Chaoweeraprasit, Polkovskyi, Xu, Daniel, Ellsworth, Levy · Couzo certificates 2026-10-10 · packet · register
2026-10-11 published T-151
Nine exact rational packings from SQUISH's fourth request
V3 C3 Upper bound confirmed superseded by T-224
Chaoweeraprasit after Couzo, Gupta, Ellsworth, Friedman, Levy · SQUISH fourth request 2026-10-11 · packet · register
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-224
PingYou Ltd after Friedman, Ellsworth, Daniel, Xu, Barnett, Couzo, Ostashev, Chaoweeraprasit, Gupta, Fang, Polkovskyi, Levy · PingYou PR 574 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
2026-10-20 published T-224 this result
Daniel's smaller n270 packing, another arrangement found from Chaoweeraprasit's, certified exactly
V3 C3 Upper bound confirmed
Daniel after Chaoweeraprasit, Levy · Daniel n270 sweep 2026-10-20 · packet · register
Links
- On this site
- Case record, · Frontier row, · T-224 in the results table
On GitHub, at main
- Register
- T-224 in
results.yaml, line 30618 - Evidence
E-evand-703-n270-report·E-evand-703-n270-exact-feasibility- Proofs and certificates
- certificate
candidates - Sources
- Daniel n270 sweep 2026-10-20 (its own site, retained copy)
- Source packet
resources/web/evand-n270-sweep-2026-10-20/README.md- Artifacts
10 artifacts and controls
resources/web/evand-n270-sweep-2026-10-20/README.mdresources/web/evand-n270-sweep-2026-10-20/acquisition/claims.jsonresources/web/evand-n270-sweep-2026-10-20/source/search/packer/candidates/s270_sw.certresources/web/evand-n270-sweep-2026-10-20/receipts/exact-certification.json.xzdevtools/upper_bound_reports.pydocs/project/reviews/review-2026-10-21-upper-bound-import-703.mdresources/web/evand-n270-sweep-2026-10-20/review/review-2026-10-21/README.mdtests/test_upper_bound_reports.pytests/test_upper_bound_reports_703.pyresources/web/evand-n270-sweep-2026-10-20/receipts/exact-certification.json.xz- Case file
frontier/n-270.md(verified lower, verified upper, reported lower, reported upper)