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 A027157 #5 Mar 30 2012 18:56:14 %S A027157 1,2,1,3,3,4,4,6,8,4,5,10,24,12,16,6,15,40,36,32,16,7,21,76,76,144,48, %T A027157 64,8,28,112,152,256,192,128,64,9,36,176,264,672,448,768,192,256,10, %U A027157 45,240,440,1088,1120,1408,960,512,256,11,55,340,680 %N A027157 Triangular array T given T(n,k)=(1/2)*t(n+1,k+1), 0<=k<=n, n >= 0, t given by A027144. %K A027157 nonn,tabl %O A027157 1,2 %A A027157 _Clark Kimberling_