English

The n-queens solution count Q(n) is divisible by 4

Combinatorics 2026-01-12 v1

Abstract

We consider the classical nn-queens problem, which asks how many ways one can place nn mutually non-attacking queens on an nn x nn chessboard. We prove that the total number of solutions to the nn-queens problem Q(n)Q(n) is divisible by 4 whenever n6n \ge 6.

Cite

@article{arxiv.2601.05856,
  title  = {The n-queens solution count Q(n) is divisible by 4},
  author = {Hugo Nielsen},
  journal= {arXiv preprint arXiv:2601.05856},
  year   = {2026}
}

Comments

6 pages, 3 figures

R2 v1 2026-07-01T08:57:50.764Z