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 A025191 #10 Aug 06 2024 00:03:42
%S A025191 1,1,4,11,33,97,288,855,2544,7577,22590,67399,201215,601017,1795966,
%T A025191 5368659,16053417,48015873,143649102,429842511,1286452725,3850770081,
%U A025191 11528245602,34517105907,103360732956,309543786441,927106804368,2776994293355
%N A025191 a(n) = Sum_{k=0..n} T(n,k), where T is the array defined in A025177.
%C A025191 Conjectures: a(n) = A027914(n)-A027914(n-1) = (A081673(n)-A081673(n-1))/2.
%K A025191 nonn
%O A025191 0,3
%A A025191 _Clark Kimberling_
%E A025191 a(1) corrected by _Jason Yuen_, Aug 05 2024