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 A059476 #8 Jan 17 2021 11:16:18 %S A059476 1,2,40,6860,9779616,114640611228,10995014015567296, %T A059476 8604220484134405095680,54849585336544518476372715520, %U A059476 2845241019832977820277705514596768000,1200139922362764777157943140382976769515000000 %N A059476 Number of 4n X 4n quarter-turn symmetric alternating-sign matrices (QTSASM's). %H A059476 G. Kuperberg, <a href="https://arxiv.org/abs/math/0008184">Symmetry classes of alternating-sign matrices under one roof</a>, arXiv:math/0008184 [math.CO], 2000-2001. %F A059476 a(n) = A059475(n)*A005130(n)^2. %K A059476 nonn %O A059476 0,2 %A A059476 _N. J. A. Sloane_, Feb 04 2001