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 A026891 #4 Mar 30 2012 18:56:11 %S A026891 1,1,3,4,12,17,51,74,224,328,1008,1478,4630,6767,21663,31472,103100, %T A026891 148642,498520,712648,2446218,3466398,12167456,17093556,61276838, %U A026891 85380372,312096590,431554188,1605820974,2205077509 %N A026891 a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), m=[ (n+1)/2 ], T given by A026769. %K A026891 nonn %O A026891 1,3 %A A026891 _Clark Kimberling_