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 A048120 #4 Mar 30 2012 18:56:54 %S A048120 0,0,2,6,24,84,312,1140,4248,15852,59688,225624,857424,3270216, %T A048120 12518472,48062520,185034360,714038448,2761343064,10698992304, %U A048120 41525207448,161418403008,628356425856,2449152822168,9557303840184 %N A048120 a(n)=T(2n,n+1), where T is given by A048113. %K A048120 nonn %O A048120 1,3 %A A048120 _Clark Kimberling_