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 A224318 #17 Nov 28 2019 07:51:55 %S A224318 1,1,2,6,24,118,661,4011,25654,170420,1165697 %N A224318 Number of 2-vexillary permutations in S_n, that, permutations whose Stanley symmetric function has at most 2 terms or at most 2 Edelman-Greene tableaux. %C A224318 This family is characterized by a finite set of permutation patterns. %H A224318 S. Billey and B. Pawlowski, <a href="https://arxiv.org/abs/1304.7870">Permutation Patterns, Stanley symmetric functions and generalized Specht modules</a>, arXiv:1304.7870 [math.CO], 2013. %H A224318 Elizabeth Hartung, Hung Phuc Hoang, Torsten Mütze, Aaron Williams, <a href="https://arxiv.org/abs/1906.06069">Combinatorial generation via permutation languages. I. Fundamentals</a>, arXiv:1906.06069 [cs.DM], 2019. %Y A224318 Cf. A005802, A223905, A224287. %K A224318 nonn,more %O A224318 0,3 %A A224318 _Sara Billey_, Apr 03 2013 %E A224318 a(0)=1 prepended by _Alois P. Heinz_, Jul 31 2019