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 A233973 #8 Dec 22 2013 00:06:56
%S A233973 0,0,1,5,9,13,32,54,82,116,159,199,227,273,331,380,429,487,536,609,
%T A233973 679,743,816,895,953,1008,1042,1067,1104,1180,1253,1332,1429,1532,
%U A233973 1626,1675,1733,1812,1921,2045,2169,2317,2420,2535,2656,2756,2850,2953
%N A233973 a(n) = A232221(n)/4.
%F A233973 a(n) = (Sum_{i=1..n} (A077068(i)-A077065(i)))/4.
%Y A233973 Cf. A001358, A077065, A077068, A232221.
%K A233973 nonn
%O A233973 1,4
%A A233973 _Omar E. Pol_, Dec 18 2013