T-230: Daniel's smaller n303 packing, started from Ostashev's packing, certified exactly
V3 C3 Upper bound confirmed superseded by T-240
One complete rational source certificate reports a finite upper-bound improvement at the exact side it states: = 17.90977221727432777221725641764, 1.86e-4 below T-186, the case's house best packing when it was reported.
The certificate and its duplicate-square and outside-container controls were decided here on 22 October 2026 by both maintained exact routes, and the frozen comparison rebuilt. No route here is the source's code, but both read it through an adapter that carries two of the source checkers' expressions transcribed, so the replay shares those components with the producer (RF-1). The 22 October review decided the certificate again on a clean-room checker of its own and found no blocking defect, so the bound is confirmed, independently re-implemented.
Issue 728 reports a packing found by Daniel's search from Ostashev's packing (#562, T-162, the house's packing through T-186): a basin explorer, near-record sweeps and crossovers, and a final band flip, which reflects one of the packing's two tilted bands along its wall. Measured here pose by pose, it is another arrangement than the house's, not a refinement of it. The issue states a dilation certificate of a binary64 packing, scaled by 1 + 10^-12, and leaves local optimality unresolved: the author's exact solver finds the packing not first-order jammed, and a further descent of about 4.8e-7 is predicted and not realised. The source's credits say the work was done with Claude (Anthropic) under Daniel's direction.
Significance, composition and next rung
- Significance
- A new arrangement at 303, 1.86e-04 below the case and every report there, found from Ostashev's packing, as T-197 at 155 (1.64e-04) is; 64 squares lie beyond a tenth of the house's packing and 24 tilts are reversed, against T-197's 29 and the 15 of T-224 and T-221 beyond a tenth, 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 22 October, is retained.
- Novelty
- previously-published Present in an identified source
The case
As published
Proven
- exact
Citation record n-303
lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)
upperLavrentev & Couzo, GitHub (confirmed T-240)
Open
- optimality
The case record
Results on the case
18 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-240
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
2026-10-03 published T-092
Smaller packings again at seven counts from to , each certified two independent ways
V3 C3 Upper bound confirmed superseded by T-240
Couzo · franciscouzo square-packing 2026-10-03 · packet · 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-240
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-240
Chaoweeraprasit after Ellsworth · SQUISH ten packings 2026-10-07 · 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-240
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 superseded by T-240
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-240
Polkovskyi after Stenlund, Friedman, Ellsworth, Chaoweeraprasit, Couzo, Xu, Gupta, Daniel, Levy · Mishapolk decimal poses 2026-10-09 · packet · register
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-240
Daniel after Xu, Chaoweeraprasit, Polkovskyi, Levy · Daniel regularized lists 2026-10-10 · packet · register
2026-10-12 published T-162
New packings of 129, 204 and 303 squares, a cut-out and two compositions, each certified exactly
V3 C3 Upper bound confirmed superseded by T-240
Ostashev after Nakajima, Chaoweeraprasit, Daniel, Xu, Levy · Ostashev compositions 2026-10-12 · 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-240
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
2026-10-14 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-240
Polkovskyi after Ostashev, Couzo, PingYou Ltd, Levy · Mishapolk KKT refinements 2026-10-14 · packet · register
2026-10-22 published T-230 this result
Daniel's smaller n303 packing, started from Ostashev's packing, certified exactly
V3 C3 Upper bound confirmed superseded by T-240
Daniel after Ostashev, Levy · Daniel n303 2026-10-22 · packet · register
2026-10-23 published T-239
Kristiansen's smaller n303 packing, found from Daniel's packing, certified exactly
V3 C3 Upper bound confirmed superseded by T-240
Kristiansen after Daniel, Ostashev, Levy · Kristiansen n303 2026-10-23 · packet · register
2026-10-23 published T-240
Couzo's 268 and 303 of #763, below T-174 and T-239, from Kaggle notebook packings
V3 C3 Upper bound confirmed
Couzo after Lavrentev, Tymchishin, Muglich, Polkovskyi, Daniel, Fang, de Winter, Levy · Couzo issue 763 2026-10-23 · packet · register
Links
- On this site
- Case record, · Frontier row, · T-230 in the results table
- Issues
- Issue #728
On GitHub, at main
- Register
- T-230 in
results.yaml, line 32626 - Evidence
E-evand-728-n303-report·E-evand-728-n303-exact-feasibility·E-evand-728-n303-review-exact-feasibility- Proofs and certificates
- certificate
candidates - Sources
- Daniel n303 2026-10-22 (its own site, retained copy)
- Source packet
resources/web/evand-n303-2026-10-22/README.md- Artifacts
12 artifacts and controls
resources/web/evand-n303-2026-10-22/README.mdresources/web/evand-n303-2026-10-22/acquisition/claims.jsonresources/web/evand-n303-2026-10-22/source/search/packer/candidates/s303_r303w0.certresources/web/evand-n303-2026-10-22/receipts/exact-certification.json.xzresources/web/evand-n303-2026-10-22/measure/identity.jsondevtools/upper_bound_reports.pydocs/project/reviews/review-2026-10-22-daniel-728.mdresources/web/evand-n303-2026-10-22/review/review-2026-10-22/README.mdtests/test_upper_bound_reports.pytests/test_upper_bound_reports_728.pyresources/web/evand-n303-2026-10-22/receipts/exact-certification.json.xzresources/web/evand-n303-2026-10-22/review/review-2026-10-22/outputs/sharp-controls.json- Case file
frontier/n-303.md(verified lower, verified upper, reported lower, reported upper)