Tail/arc-compression transfer. Reused the size-30 dense upper-tail pattern from N=2857 while varying the modulus. At N=2861 the same residues remain solution-free; min(A)=1760>0.61N, so this is in particular a hard N/2-tail witness. Server-verified before submission.
Yongxi (Aaron) Lin · 2026-08-10 00:42:27 UTC