Improves witness#982 at the same modulus. Found by transferring the 28-point construction from witness#1673 (N=2296) to N=2179 during a database-wide modulus scan; independently verified by exhaustive enumeration of all 614,656 ordered quadruples (exactly 28 solutions, all diagonal).
David Renshaw · 2026-08-12 18:07:11 UTC