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 A263863 #8 Oct 31 2015 14:43:29 %S A263863 1,1,1,1,1,1,2,0,1,1,1,3,3,2,2,0,3,0,0,0,1,1,1,3,5,8,5,7,4,8,2,5,1,5, %T A263863 0,3,0,0,0,4,0,0,0,0,0,0,0,1 %N A263863 Triangle read by rows: T(n,k) (n>=0, k>=n+1) is the number of posets with n elements and k chains. %C A263863 Row sums give A000112. %H A263863 FindStat - Combinatorial Statistic Finder, <a href="http://www.findstat.org/StatisticsDatabase/St000180">The number of chains of a poset</a>. %e A263863 Triangle begins: %e A263863 1, %e A263863 1, %e A263863 1,1, %e A263863 1,1,2,0,1, %e A263863 1,1,3,3,2,2,0,3,0,0,0,1, %e A263863 1,1,3,5,8,5,7,4,8,2,5,1,5,0,3,0,0,0,4,0,0,0,0,0,0,0,1, %e A263863 ... %Y A263863 Cf. A000112. %K A263863 nonn,tabf %O A263863 0,7 %A A263863 _Christian Stump_, Oct 28 2015