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 A144887 #5 Jul 03 2023 10:06:12
%S A144887 1,5,25,161,1081,8745,75305,741961,7904201,93174025,1185282185,
%T A144887 16364262281,242055376521,3834244039305,64590031280265,
%U A144887 1154392672267401,21796700933039241,433694961594395785,9066521908425387145,198692729793556061321
%N A144887 Row sums of triangle A144886 (S1hat(4)).
%F A144887 a(n) = Sum_{m=1..n} A144886(n,m), n>=1.
%Y A144887 Cf. A144886.
%K A144887 nonn,easy
%O A144887 1,2
%A A144887 _Wolfdieter Lang_, Oct 09 2008