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

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

Author

Guillaume Escamocher, May 03 2021

Keywords

• nonn
• more
• hard

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

• Guillaume Escamocher and Barry O'Sullivan, Leprechauns on the chessboard, Discrete Mathematics, 344(5), 2021.

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