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 A053199 #5 Mar 30 2012 18:57:01
%S A053199 1,2,3,3,5,14,4,7,21,60,5,9,28,84,246,6,11,35,108,328,980,7,13,42,132,
%T A053199 410,1260,3824,8,15,49,156,492,1540,4780,14688,9,17,56,180,574,1820,
%U A053199 5736,17952,55720,10,19,63,204,656,2100,6692
%N A053199 Triangular array T: put T(n,0)=n+1 for all n >= 0 and all other T(n,k)=0; then put T(n,k)=Sum{T(i,j): 0<=j<=i-n+k, n-k<=i<=n}.
%e A053199 Rows: {1}, {2,3}, {3,5,14}, {4,7,21,60}, ...
%K A053199 nonn,tabl
%O A053199 0,2
%A A053199 _Clark Kimberling_, Mar 18 2000