A189872 Number of ways to place n nonattacking composite pieces queen + leaper[4,5] on an n X n chessboard.

1, 0, 0, 2, 10, 4, 12, 32, 96, 144, 576, 2280, 11988, 47128, 232756, 1290772, 7383588, 46039788, 311958088, 2263575696, 16975534432

Offset: 1

Author

Vaclav Kotesovec, Apr 29 2011

Keywords

• nonn
• hard

Comments

a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+4)-p(i)|<>5 AND |p(j+5)-p(j)|<>4 AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+4<=n, j+5<=n, m+k<=n

Links

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

Crossrefs

Cf. A051223, A189866, A189869, A189871, A189570