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A225740
Number of arrangements of n nonattacking Queens on an n X n board, with no Queens on both main diagonals.
2
0, 0, 0, 2, 0, 4, 0, 12, 8, 12, 64, 760, 2080, 11524, 77672, 454376, 2972720, 19274208, 160500016, 1150812148, 9797154696, 79646705916, 771589104392
OFFSET
1,4
LINKS
V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p.447
Vaclav Kotesovec, example, board 8x8, no queens on line a1-h8 and no queens on line a8-h1
EXAMPLE
From Martin Ehrenstein, Jan 10 2022: (Start)
Solutions for n=9 filtered from the Coserea link in A000170:
3 5 8 2 9 7 1 4 6
3 6 9 2 8 1 4 7 5
4 6 9 3 1 8 2 5 7
5 3 6 9 2 8 1 4 7
5 7 4 1 8 2 9 6 3
6 4 1 7 9 2 8 5 3
7 4 1 8 2 9 6 3 5
7 5 2 8 1 3 9 6 4
(End)
CROSSREFS
Sequence in context: A285773 A137449 A056946 * A349479 A111757 A286122
KEYWORD
nonn,more,hard
AUTHOR
Vaclav Kotesovec, Aug 04 2013
EXTENSIONS
a(9)-a(19) corrected and extended with a(20)-a(23) by Martin Ehrenstein, Jan 10 2022
a(9)-a(19) confirmed by Vaclav Kotesovec, Jan 11 2022
STATUS
approved