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Nonattacking queens on a 2n+1 X 2n+1 toroidal board, solutions which differ only by rotation, reflection or torus shift count only once.
6

%I #7 Jul 12 2018 20:27:57

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

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

%D 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).

%H I. Rivin, I. Vardi and P. Zimmermann, <a href="https://www.jstor.org/stable/2974691">The n-queens problem</a>, Amer. Math. Monthly, 101 (1994), 629-639 (for finding the solutions).

%Y A007705, A006841, A051906.

%K hard,nice,nonn

%O 0,6

%A _Matthias Engelhardt_, Apr 05 2000

%E More terms from _Matthias Engelhardt_, Jan 11 2001