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 A144276 #6 Jul 02 2023 06:06:27
%S A144276 1,3,13,97,997,13585,225625,4454801,101415881,2618639033,75524367593,
%T A144276 2406745316697,83950853842617,3181371937414425,130135485102246265,
%U A144276 5714800778645325881,268144898273200109561,13387708871579930596793,708640690235801235876153
%N A144276 Row sums of triangle A144275 (called S2hat(-2)).
%F A144276 a(n) = Sum_{m=1..n} A144275(n,m), n>=1.
%Y A144276 Cf. A144275.
%K A144276 nonn,easy
%O A144276 1,2
%A A144276 _Wolfdieter Lang_, Oct 09 2008