A059492 Expansion of generating function A_{UO}^(1)(8n).

1, 1, 9, 676, 417316, 2105433225, 86576511622500, 28972583638980195600, 78831929114313969179740176, 1742936131827576565608759271801924, 312998895971128640129284150531179425539849, 456409483679643917229799018559460369930900420149904

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..47

G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv:math/0008184 [math.CO], 2000-2001 [Th. 5].

Formula

a(n) = A005156(n)^2.

Mathematica

Table[(1/4^n)*(Product[((6 k - 2)! (2 k - 1)!)/((4 k - 1)! (4 k - 2)!), {k, n}])^2, {n, 0, 20}] (* G. C. Greubel, Sep 10 2017 *)

Crossrefs

Sequence in context: A287937 A372184 A053973 * A322488 A109061 A332169

Adjacent sequences: A059489 A059490 A059491 * A059493 A059494 A059495

Keyword

nonn,easy

Author

N. J. A. Sloane, Feb 04 2001

Status

approved