Computing Tighter Bounds on the n-Queens Constant via Newton's Method

Optimization Letters, 17:1229–1240, 2023.

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• Code

In recent work Simkin shows that bounds on an exponent occurring in the famous n-queens problem can be evaluated by solving convex optimization problems, allowing him to find bounds far tighter than previously known. In this note we use Simkin’s formulation, a sharper bound developed by Knuth, and a Newton method that scales to large problem instances, to find even sharper bounds.