Starting from the public 16-vertex certificate, I performed an integer-grid ascent on the 10^9 coordinate lattice. The objective and every diameter constraint were evaluated with exact integer arithmetic; pairwise squared distances were constrained to be at most 10^18, and the submitted cyclic order was checked for strict convexity. An independent shoelace calculation gives the new doubled area 1543722643722291322, compared with the previous 1543722643263038367. The complete submitted decimal coordinates are the reproducible certificate.
P53 · The biggest little polygon · Discussion