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 A144281 #6 Jul 02 2023 12:48:14
%S A144281 1,4,25,265,3793,70789,1600429,42811078,1316981794,45858363502,
%T A144281 1781106761686,76349861206627,3579325969675135,182170488961796899,
%U A144281 10002072131444031160,589261706147357617009,37076870479319887575253,2481442922857293505594237
%N A144281 Row sums of triangle A144280 (called S2hat(-3)).
%F A144281 a(n) = Sum_{m=1..n} A144280(n,m), n>=1.
%Y A144281 Cf. A144280.
%K A144281 nonn,easy
%O A144281 1,2
%A A144281 _Wolfdieter Lang_, Oct 09 2008