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 A233001 #8 Oct 09 2020 03:51:16 %S A233001 1,4,81,73984,347138964225,266749070875738835911704576, %T A233001 153420859074097275505001068428834200016791982521508695409921 %N A233001 a(n) = A005271(n)^2. %H A233001 Daryl DeFord, <a href="http://dx.doi.org/10.2140/involve.2014.7.787">Seating rearrangements on arbitrary graphs</a>, Involve, Vol. 7 (2014), No. 6, 787-805. See Table 3. %Y A233001 Cf. A005271. %K A233001 nonn,more,hard %O A233001 1,2 %A A233001 _N. J. A. Sloane_, Dec 17 2013