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.

A189840 Number of ways to place n nonattacking composite pieces rook + rider[4,4] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 108, 544, 3264, 23040, 171072, 1409664, 12916224, 131217408, 1428028032, 16709309440, 210367491840, 2847184825728
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(j+4k)-p(j)|<>4k for all j>=1, k>=1, j+4k<=n

Links

Crossrefs

Cf. A189255, A000170, A189838, A189839

A189844 Number of ways to place n nonattacking composite pieces rook + semi-rider[3,3] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 22, 98, 534, 3334, 23724, 191820, 1704532, 16689868, 179288892, 2069311996, 25760882744, 345073745880, 4900331447624
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(j+3k)-p(j)<>3k for all j>=1, k>=1, j+3k<=n.
For information about semi-pieces see semi-bishop (A187235) and semi-queen (A099152).

Links

Crossrefs

Cf. A189282, A099152, A189843, A189839, A187235

A189841 Number of ways to place n nonattacking composite pieces rook + rider[5,5] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 120, 672, 4128, 28992, 231936, 2088960, 20017152, 207208704, 2326900992, 28338241536, 373152276480, 5206300028928
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(j+5k)-p(j)|<>5k for all j>=1, k>=1, j+5k<=n

Links

Crossrefs

Cf. A189256, A000170, A189838, A189839, A189840

A189842 Number of ways to place n nonattacking composite pieces rook + rider[6,6] on an n X n chessboard.

Original entry on oeis.org

1, 2, 6, 24, 120, 720, 4800, 34752, 280512, 2528256, 25282560, 278323200, 3242649600, 40330371072, 536528954880, 7633092132864
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(j+6k)-p(j)|<>6k for all j>=1, k>=1, j+6k<=n

Links

Crossrefs

Cf. A189271, A000170, A189838, A189839, A189840, A189841
Showing 1-4 of 4 results.

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

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