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.

Previous Showing 21-24 of 24 results.

A245011 Number of ways to place n nonattacking princesses on an n X n board.

Original entry on oeis.org

1, 4, 6, 86, 854, 9556, 146168, 2660326, 56083228, 1349544632, 36786865968, 1117327217782
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 16 2014

Keywords

Comments

A princess moves like a bishop and a knight.

Links

Crossrefs

Cf. A201513, A000170, A002465, A201540.
Cf. A185085, A051223, A244284, A201511, A201861, A137774.
Cf. A225555.

A343905 Number of ways of placing n nonattacking range-3 leprechauns on an n X n board.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 34, 4, 112, 516, 7312, 81324, 1056560, 13443944, 171919446, 2195838076, 28876216900, 379982087060
Offset: 1

Views

Author

Guillaume Escamocher, May 03 2021

Keywords

Comments

First 25 terms were computed by Vaclav Kotesovec in 2020.
A range-k leprechaun is a fairy chess piece that can move to any square within range k, and to any square that a queen can move to (Escamocher and O'Sullivan 2021). A range-1 leprechaun is a queen, a range-2 leprechaun is a superqueen.

Links

Crossrefs

Cf. A000170, A051223, A343907.

Extensions

a(26)-a(27) from Martin Ehrenstein, May 06 2021
a(26) confirmed by Vaclav Kotesovec, Jun 07 2021
a(28) from Martin Ehrenstein, Oct 14 2021

A178986 Number of ways to place n nonattacking amazons (superqueens) on an n X n toroidal board.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44, 0, 1092, 0, 0, 0, 16932, 0, 24776, 0, 0, 0, 1881492, 0
Offset: 1

Views

Author

Vaclav Kotesovec, Jan 03 2011

Keywords

Comments

An amazon (superqueen) moves like a queen and a knight.

Links

Crossrefs

Cf. A051223, A051906, A085801, A000170, A178975.

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

Original entry on oeis.org

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

Crossrefs

Cf. A051223, A189866, A189869, A189871, A189570
Previous Showing 21-24 of 24 results.

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

Content is available under The OEIS End-User License Agreement.