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 A089834 #4 Oct 17 2015 08:36:24 %S A089834 0,0,10,139,2570,48782,1038146 %N A089834 Number of distinct non-recursive Catalan bijections whose minimum clause-representation requires examination of n nodes in total and which require more than one non-default clause. %C A089834 Row sums of A089831 excluding the first column. %Y A089834 a(n) = A089832(n)-A089833(n). %K A089834 nonn %O A089834 1,3 %A A089834 _Antti Karttunen_, Dec 05 2003