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 A047129 #5 Mar 30 2012 18:56:53 %S A047129 1,1,6,28,166,971,5937,36736,230363,1458037,9292357,59576614, %T A047129 383721187,2481397399,16099317872,104753149406,683279530195, %U A047129 4466548322041,29253296829696,191917744224242,1260998821726319,8296736705457073 %N A047129 T(2n,n), array T as in A047120. %K A047129 nonn %O A047129 0,3 %A A047129 _Clark Kimberling_. Definition revised Dec 08 2006