A189880 Number of ways to place n nonattacking composite pieces queen + rider[3,5] on an n X n chessboard.

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

Links

Table of n, a(n) for n=1..21.

V. Kotesovec, Number of ways of placing non-attacking queens, kings, bishops and knights (in English and Czech)

Wikipedia, Fairy chess piece

Crossrefs

Cf. A102388, A189875, A189878, A189859, A189879

Sequence in context: A364253 A189874 A189865 * A189871 A096877 A058297

Adjacent sequences: A189877 A189878 A189879 * A189881 A189882 A189883

Keyword

nonn,hard

Author

Vaclav Kotesovec, Apr 29 2011

Status

approved