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 A026303 #4 Mar 30 2012 18:56:06 %S A026303 1,3,20,147,1143,9163,74919,621015,5199909,43878315,372530781, %T A026303 3178551148,27231924300,234113134518,2018601251793,17449264269081, %U A026303 151169392399773 %N A026303 a(n) = T(3n,n), where T is the array in A026300. %K A026303 nonn %O A026303 0,2 %A A026303 _Clark Kimberling_