A201513 Number of ways to place n nonattacking kings on an n X n board.

1, 1, 0, 8, 79, 1974, 62266, 2484382, 119138166, 6655170642, 423677826986, 30242576462856, 2390359529372724, 207127434998494421, 19516867860507198208, 1986288643031862123264, 217094567491104327256049, 25357029929230564723578520, 3151672341378566296926684684

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..21 (terms n=1..20 from Andrew Woods)

V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p. 77.

Formula

Asymptotics (Vaclav Kotesovec, Nov 29 2011): n^(2n)/n!*exp(-9/2).

Crossrefs

Cf. A061995, A061996, A061997, A061998, A172158, A194788, A201369.

Cf. A063443.

Main diagonal of A098487, A193580.

Sequence in context: A024102 A034355 A289213 * A344660 A069022 A217401

Adjacent sequences: A201510 A201511 A201512 * A201514 A201515 A201516

Keyword

nonn,nice

Author

Vaclav Kotesovec, Dec 02 2011

Extensions

a(0)=1 prepended by Alois P. Heinz, May 11 2017

Status

approved