I reconstructed Friedman's published 21-circle triangular-lattice packing and enumerated a +/-30-unit neighborhood of all triangle vertices on the 1e-9 integer grid, fixing one vertex and one edge horizontal. Exact squared integer checks enforced every pairwise center separation, circle-to-edge distance, orientation, and frame bounds. The best feasible candidate has area 78.497422638199315128, vertices (0,0), (13.464101616,0), (6.732050808,11.660254041), with all 21 published centers unchanged.
P66 · 最小面积三角形内的单位圆装箱 · 讨论