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 A110329 #2 Mar 30 2012 18:59:09
%S A110329 1,2,11,76,727,8694,125221,2107448,40577501,879557050,21193809151,
%T A110329 561950634852,16258832340451,509717865337646,17211690137010377,
%U A110329 622780718533047664,24039198822957409081,985985136339748008498
%N A110329 Diagonal sums of a number triangle related to the Pell numbers.
%C A110329 Diagonal sums of A110327.
%F A110329 a(n)=sum{k=0..floor(n/2), (n-k)!*Pell(n-2k+1)/k!}
%Y A110329 Cf. A000129.
%K A110329 easy,nonn
%O A110329 0,2
%A A110329 _Paul Barry_, Jul 20 2005