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 A126453 #3 Mar 30 2012 18:37:02
%S A126453 1,3,15,218,7273,434654,40417797,5369210845,962496995941,
%T A126453 223528473482380,65221305164439085,23343099723197369886,
%U A126453 10052235133879615066675,5126300310101866339983229
%N A126453 Row sums of triangle A126450: a(n) = Sum_{k=0..n} C( C(n+2,3) - C(k+2,3) + 1, n-k).
%o A126453 (PARI) a(n)=sum(k=0,n,binomial(binomial(n+2,3)-binomial(k+2,3)+1, n-k))
%Y A126453 Cf. A126450; A126451, A126452.
%K A126453 nonn
%O A126453 0,2
%A A126453 _Paul D. Hanna_, Dec 27 2006