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 A047097 #4 Mar 30 2012 18:56:53 %S A047097 1,4,16,60,228,860,3267,12426,47471,181812,698512,2690086,10384712, %T A047097 40170182,155681112,604362074,2349783665,9148780570,35665860725, %U A047097 139202880860,543887439194,2127148912456,8326877989146,32623644335536 %N A047097 T(n,n+3), array T as in A047089. %K A047097 nonn %O A047097 0,2 %A A047097 _Clark Kimberling_