This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A059493 #5 Mar 30 2012 16:49:03
%S A059493 1,36,58800,4350842496,14616841474819584,2232275367429083934397440,
%T A059493 15508029030753757178368051489382400,
%U A059493 4903022043055128535359103830176804216217600000,70564996915837622037116996413540007182305594153356328960000
%N A059493 A005156(n)*A059488(n)^2.
%H A059493 G. Kuperberg, <a href="http://arXiv.org/abs/math.CO/0008184">Symmetry classes of alternating-sign matrices under one roof, arXiv math.CO/0008184</a> [A_{UU}(4n)]
%Y A059493 Cf. A005156, A059488, A107445.
%K A059493 nonn,easy
%O A059493 0,2
%A A059493 _N. J. A. Sloane_, Feb 04 2001
%E A059493 Definition changed by _N. J. A. Sloane_ following a comment by Paul Zinn-Justin (pzinn(AT)lptms.u-psud.fr), May 29 2007