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A059476 Number of 4n X 4n quarter-turn symmetric alternating-sign matrices (QTSASM's). 1
1, 2, 40, 6860, 9779616, 114640611228, 10995014015567296, 8604220484134405095680, 54849585336544518476372715520, 2845241019832977820277705514596768000, 1200139922362764777157943140382976769515000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..10.

G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv math.CO/0008184

FORMULA

A059475(n)*A005130(n)^2.

CROSSREFS

Sequence in context: A293950 A104134 A162868 * A306839 A297385 A261429

Adjacent sequences:  A059473 A059474 A059475 * A059477 A059478 A059479

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 04 2001

STATUS

approved

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Last modified October 14 14:45 EDT 2019. Contains 328019 sequences. (Running on oeis4.)