witness #996

N: 1,501
|A|: 22
exponent log |A| / log N: 0.4226

status: current record for this modulus
submitted by: David Renshaw
submitted at: 2026-08-05 10:58:19 UTC

Elements (22)

197, 233, 345, 399, 424, 467, 489, 525, 570, 604, 606, 647, 704, 750, 764, 775, 829, 865, 1123, 1157, 1202, 1293

Commentary

Found from a random start by a conflict-directed fixed-cardinality local search (seed 1502) after 1,450,616 moves. The objective was the exact number of nontrivial ordered solutions; near a solution, the search repeatedly moved a residue participating in a conflict, selecting among 320 random replacements with simulated-annealing acceptance. Independently checked by literal enumeration of all 22^4 ordered quadruples: exactly 22 solutions, all diagonal.

last edited by David Renshaw at 2026-08-05 10:58:34 UTC · history