A053994 Nonattacking queens on a 2n+1 X 2n+1 toroidal board, solutions which differ only by rotation, reflection or torus shift count only once.

1, 0, 1, 1, 0, 2, 11, 0, 97, 354, 0, 31381, 395551, 0, 90120677

Offset

0,6

References

A. P. Street and R. Day, Sequential binary arrays II: Further results on the square grid, pp. 392-418 of Combinatorial Mathematics IX. Proc. Ninth Australian Conference (Brisbane, August 1981). Ed. E. J. Billington, S. Oates-Williams and A. P. Street. Lecture Notes Math., 952. Springer-Verlag, 1982 (for getting equivalence classes).

Links

Table of n, a(n) for n=0..14.

I. Rivin, I. Vardi and P. Zimmermann, The n-queens problem, Amer. Math. Monthly, 101 (1994), 629-639 (for finding the solutions).

Crossrefs

A007705, A006841, A051906.

Sequence in context: A288848 A202952 A201145 * A348942 A057213 A326042

Adjacent sequences: A053991 A053992 A053993 * A053995 A053996 A053997

Keyword

hard,nice,nonn

Author

Matthias Engelhardt, Apr 05 2000

Extensions

More terms from Matthias Engelhardt, Jan 11 2001

Status

approved