A032522 Number of point symmetric solutions to non-attacking queens problem on n X n board.

1, 0, 0, 2, 2, 4, 8, 4, 16, 12, 48, 80, 136, 420, 1240, 3000, 8152, 18104, 44184, 144620, 375664, 1250692, 3581240, 11675080, 34132592, 115718268, 320403024, 1250901440, 3600075088, 14589438024, 43266334696, 181254386312

Offset: 1

Author

Miklos SZABO (mike(AT)ludens.elte.hu)

Keywords

• nonn
• nice
• hard

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• R. J. Walker, An enumerative technique for a class of combinatorial problems, pp. 91-94 of Proc. Sympos. Applied Math., vol. 10, Amer. Math. Soc., 1960.

Links

• W. Schubert, Table of n, a(n) for n = 1..40
• Tricia M. Brown, Kaleidoscopes, Chessboards, and Symmetry, Journal of Humanistic Mathematics, Volume 6 Issue 1 ( January 2016), pages 110-126.
• Gheorghe Coserea, Solutions for n=10.
• Gheorghe Coserea, Solutions for n=11.
• Gheorghe Coserea, MiniZinc model for generating solutions.
• W. Schubert, N-Queens page
• M. Szabo, Non-attacking Queens Problem Page

Crossrefs

Cf. A002562, A033148, A037224, A037223.

Extensions

More terms for n = 33..36 from W. Schubert, Jul 31 2009