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 A263858 #8 Oct 31 2015 14:39:13 %S A263858 1,1,1,1,1,3,1,1,7,6,2,1,13,25,18,4,2 %N A263858 Triangle read by rows: T(n,k) (n>=0, k>=1) is the number of posets with n elements and k maximal chains. %C A263858 Row sums give A000112. %H A263858 FindStat - Combinatorial Statistic Finder, <a href="http://www.findstat.org/StatisticsDatabase/St000071">The number of maximal chains in a poset</a>. %e A263858 Triangle begins: %e A263858 1, %e A263858 1, %e A263858 1,1, %e A263858 1,3,1, %e A263858 1,7,6,2, %e A263858 1,13,25,18,4,2, %e A263858 ... %Y A263858 Cf. A000112. %K A263858 nonn,tabf,more %O A263858 0,6 %A A263858 _Christian Stump_, Oct 28 2015