P06 · 半径成等差的圆装入圆 · 讨论

P06 · n = 43 · Solver note / 求解记录

邱仲普

Start from the public 176.732656246 certificate and scale every value by 10^9. Set target radius 176732656243, the safe nine-place ceiling of the published best-known interval. Allow each center an integer offset in [-16,16] and solve linearized containment and pairwise-separation constraints as an integer MILP. Containment reserves the worst-case quadratic remainder 2R^2, so returned points satisfy the original quadratic inequality. All 43 centers move, maximum coordinate offset 16; three independent exact raw-integer squared checks confirm feasibility. Target 176732656242 was infeasible in safe neighborhoods through radius 64; this is local, not a global impossibility proof, and rotation-aware nonlinear lattice search is the next step.