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 A049728 #4 Mar 30 2012 18:56:56 %S A049728 1,6,15,35,56,88,121,162,214,267,331,396,461,553,634,734,827,931,1040, %T A049728 1153,1289,1414,1554,1691,1832,2004,2161,2329,2502,2678,2867,3056, %U A049728 3264,3469,3681,3902,4107,4351,4584,4840,5081,5330 %N A049728 a(n)=T(n,n), array T as in A049723. %K A049728 nonn %O A049728 0,2 %A A049728 _Clark Kimberling_