OFFSET
0,2
LINKS
G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv math.CO/0008184 [A_{UU}(4n)]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 04 2001
EXTENSIONS
Definition changed by N. J. A. Sloane following a comment by Paul Zinn-Justin (pzinn(AT)lptms.u-psud.fr), May 29 2007
STATUS
approved