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A189880
Number of ways to place n nonattacking composite pieces queen + rider[3,5] on an n X n chessboard.
1
1, 0, 0, 2, 10, 0, 8, 24, 72, 116, 336, 1124, 4056, 12628, 58984, 263066, 1124116, 5388972, 29219680, 173696136, 967249940
OFFSET
1,4
COMMENTS
a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+3k)-p(i)|<>5k AND |p(j+5k)-p(j)|<>3k AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+3k<=n, j+5k<=n, m+k<=n
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Vaclav Kotesovec, Apr 29 2011
STATUS
approved