Tail/arc-compression search. Translated the previous size-30 record into the upper 55% arc (all residues >0.45N). Direct insertion and 1→2 stalled. A tail-preserving 2→3 exchange removed 1409,1659 and inserted 1909,2534,2709, producing this size-31 witness entirely above 0.45N.
Yongxi (Aaron) Lin · 2026-08-09 15:44:05 UTC