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 A263929 #4 Oct 30 2015 20:56:10 %S A263929 1,1,2,6,24,120,720,5018,39374,337816,3092691,29659731,294107811, %T A263929 2988678546,30935695794,324832481490,3450158410649,36993206191004, %U A263929 399827092167771,4351269802153188 %N A263929 Number of permutations that are sortable with two stacks in series. %H A263929 Andrew Elvey-Price, Anthony J Guttmann, <a href="http://arxiv.org/abs/1510.08663">Permutations sortable by two stacks in series</a>, arXiv:1510.08663 [math.CO], (29-October-2015) %K A263929 nonn %O A263929 0,3 %A A263929 _Joerg Arndt_, Oct 30 2015