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A059476 Number of 4n X 4n quarter-turn symmetric alternating-sign matrices (QTSASM's). 2
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/0008184 [math.CO], 2000-2001.
FORMULA
a(n) = A059475(n)*A005130(n)^2.
CROSSREFS
Sequence in context: A358160 A328553 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 May 21 08:24 EDT 2024. Contains 372729 sequences. (Running on oeis4.)