cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A189855 Number of ways to place n nonattacking composite pieces rook + rider[2,4] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 60, 208, 1184, 7840, 36036, 209664, 1395480, 10996728, 83573220, 723835856, 7132494776, 77976981216, 790552134804
Offset: 1

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Author

Vaclav Kotesovec, Apr 29 2011

Keywords

Comments

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

Links

Crossrefs

Cf. A000170, A189851, A189854, A189837

A189856 Number of ways to place n nonattacking composite pieces rook + rider[2,5] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 120, 392, 1810, 10400, 72228, 589674, 3823906, 29420944, 266232984, 2711139976, 30669073348, 316482938974
Offset: 1

Views

Author

Vaclav Kotesovec, Apr 29 2011

Keywords

Comments

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

Links

Crossrefs

Cf. A000170, A189854, A189855

A189857 Number of ways to place n nonattacking composite pieces rook + rider[2,6] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 120, 720, 2952, 16064, 104800, 816160, 7327728, 74031176, 621684168, 5950876288, 64694543120, 777746708096
Offset: 1

Views

Author

Vaclav Kotesovec, Apr 29 2011

Keywords

Comments

a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+2k)-p(i)|<>6k AND |p(j+6k)-p(j)|<>2k for all i>=1, j>=1, k>=1, i+2k<=n, j+6k<=n.

Links

Crossrefs

Cf. A000170, A189854, A189855, A189856, A189853.

A189876 Number of ways to place n nonattacking composite pieces queen + rider[2,3] on an n X n chessboard.

Original entry on oeis.org

1, 0, 0, 2, 10, 0, 0, 0, 0, 16, 60, 40, 304, 620, 2512, 8734, 28410, 94312, 345824, 1391072, 5759566, 25227796, 121663032, 635977968
Offset: 1

Views

Author

Vaclav Kotesovec, Apr 29 2011

Keywords

Comments

(in fairy chess the rider [2,3] is called a Zebrarider)
a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+2k)-p(i)|<>3k AND |p(j+3k)-p(j)|<>2k AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+2k<=n, j+3k<=n, m+k<=n

Links

Crossrefs

Cf. A102388, A189873, A189854
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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