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 A026074 #5 Jun 23 2013 10:14:56 %S A026074 1,1,12,91,726,5902,48704,406353,3419020,28958955,246598716, %T A026074 2109182557,18106771400,155929895685,1346442959176,11653675471305, %U A026074 101071521560286,878176794266261,7642505705447340,66606583068846975 %N A026074 a(n) = T(3n,n), where T is the array defined in A024996. %K A026074 nonn %O A026074 0,3 %A A026074 _Clark Kimberling_