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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.

User: Guillaume Escamocher

Guillaume Escamocher's wiki page.

Guillaume Escamocher has authored 2 sequences.

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

A343907 a(n) is the least s > 1 for which it is possible to place s nonattacking range-n leprechauns on an s X s board.

Original entry on oeis.org

4, 10, 16, 28, 36, 52, 64, 82, 100
Offset: 1

Views

Author

Guillaume Escamocher, May 03 2021

Keywords

Comments

A range-n leprechaun is a fairy chess piece that can move to any square within range n, and to any square that a queen can move to. A range-1 leprechaun is a queen and a range-2 leprechaun is a superqueen. (Escamocher and O'Sullivan 2021)

Links

Crossrefs

Cf. A343905.

Formula

If n is odd, a(n) = (n+1)^2. If n is even, a(n) > (n+1)^2. (Escamocher and O'Sullivan 2021)

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

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