cp's OEIS Frontend

A225740 Number of arrangements of n nonattacking Queens on an n X n board, with no Queens on both main diagonals.

%I A225740 #29 Jan 17 2022 03:16:19
%S A225740 0,0,0,2,0,4,0,12,8,12,64,760,2080,11524,77672,454376,2972720,
%T A225740 19274208,160500016,1150812148,9797154696,79646705916,771589104392
%N A225740 Number of arrangements of n nonattacking Queens on an n X n board, with no Queens on both main diagonals.
%H A225740 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p.447
%H A225740 Vaclav Kotesovec, <a href="/A225740/a225740.jpg">example</a>, board 8x8, no queens on line a1-h8 and no queens on line a8-h1
%e A225740 From _Martin Ehrenstein_, Jan 10 2022: (Start)
%e A225740 Solutions for n=9 filtered from the Coserea link in A000170:
%e A225740   3 5 8 2 9 7 1 4 6
%e A225740   3 6 9 2 8 1 4 7 5
%e A225740   4 6 9 3 1 8 2 5 7
%e A225740   5 3 6 9 2 8 1 4 7
%e A225740   5 7 4 1 8 2 9 6 3
%e A225740   6 4 1 7 9 2 8 5 3
%e A225740   7 4 1 8 2 9 6 3 5
%e A225740   7 5 2 8 1 3 9 6 4
%e A225740 (End)
%Y A225740 Cf. A000170, A003471.
%K A225740 nonn,more,hard
%O A225740 1,4
%A A225740 _Vaclav Kotesovec_, Aug 04 2013
%E A225740 a(9)-a(19) corrected and extended with a(20)-a(23) by _Martin Ehrenstein_, Jan 10 2022
%E A225740 a(9)-a(19) confirmed by _Vaclav Kotesovec_, Jan 11 2022