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A244284 Number of ways to place n nonattacking zebras on an n X n chessboard. 4
1, 6, 84, 1168, 20502, 525796, 18939708, 802444170, 38934305898, 2170312156170 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Zebra is a (fairy chess) leaper [2,3].

LINKS

Table of n, a(n) for n=1..10.

V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p.363

Wikipedia, Fairy chess piece

FORMULA

a(n) ~ n^(2*n)/n! * exp(-9/2).

CROSSREFS

Cf. A172137, A172138, A172139, A172140.

Cf. A201540, A201511, A201861, A201513.

Sequence in context: A212701 A248338 A144514 * A011945 A113888 A163947

Adjacent sequences:  A244281 A244282 A244283 * A244285 A244286 A244287

KEYWORD

nonn,hard,more

AUTHOR

Vaclav Kotesovec, Jun 25 2014

STATUS

approved

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Last modified July 27 13:36 EDT 2021. Contains 346306 sequences. (Running on oeis4.)