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.

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.

A189877 Number of ways to place n nonattacking composite pieces queen + rider[2,4] on an n X n chessboard.

Original entry on oeis.org

1, 0, 0, 2, 0, 0, 0, 0, 0, 4, 56, 172, 680, 1348, 6576, 34568, 107624, 413760, 1697288, 8035558, 37441416, 192483420, 1115143224
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)|<>4k AND |p(j+4k)-p(j)|<>2k AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+2k<=n, j+4k<=n, m+k<=n

Links

Crossrefs

Cf. A102388, A189874, A189876, A189855

A189858 Number of ways to place n nonattacking composite pieces rook + rider[3,4] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 80, 326, 1566, 9544, 53696, 347382, 2566892, 21907934, 184868860, 1704360992, 17294597926, 192725663600, 2139133978996
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+3k)-p(i)|<>4k AND |p(j+4k)-p(j)|<>3k for all i>=1, j>=1, k>=1, i+3k<=n, j+4k<=n.

Links

Crossrefs

Cf. A000170, A189851, A189855.
Showing 1-4 of 4 results.

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

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