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 A309669 #30 Aug 28 2019 01:41:43 %S A309669 1,0,0,1,0,0,0,1,0,3,0,7,30,133,581 %N A309669 Number of ways of placing 2*n-1 nonattacking queens on a hexagonal board with edge-length n in Glinski's hexagonal chess, inequivalent up to rotations and reflections of the board. %H A309669 Chess variants, <a href="https://www.chessvariants.com/hexagonal.dir/hexagonal.html">Glinski's Hexagonal Chess</a> %H A309669 Vaclav Kotesovec, <a href="/A309669/a309669.jpg">All inequivalent solutions for n = 4, 8, 10 and 12</a> %H A309669 Wikipedia, <a href="https://en.wikipedia.org/wiki/Hexagonal_chess#Gli%C5%84ski's_hexagonal_chess">Hexagonal chess - Gliński's hexagonal chess</a> %Y A309669 Cf. A309260, A309746. %K A309669 nonn,more %O A309669 1,10 %A A309669 _Vaclav Kotesovec_, Aug 16 2019 %E A309669 a(15) from _Vaclav Kotesovec_, Aug 28 2019