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A189871
Number of ways to place n nonattacking composite pieces queen + leaper[3,5] on an n X n chessboard.
1
1, 0, 0, 2, 10, 0, 8, 24, 72, 116, 384, 1660, 7344, 24364, 130408, 743360, 4242704, 27018788, 190618152, 1431986780, 11053915716
OFFSET
1,4
COMMENTS
a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+3)-p(i)|<>5 AND |p(j+5)-p(j)|<>3 AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+3<=n, j+5<=n, m+k<=n
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Vaclav Kotesovec, Apr 29 2011
STATUS
approved