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 A027099 #8 Oct 23 2019 20:13:55
%S A027099 1,3,9,28,83,244,713,2075,6029,17512,50891,148037,431151,1257365,
%T A027099 3671731,10735948,31429745,92116592,270268647,793741973,2333221387,
%U A027099 6864280611,20210115899,59545932370,175558633893,517915132777
%N A027099 a(n) = Sum_{0<=i<=i<=n} A027082(i, n+j).
%Y A027099 Partial sums of A027098.
%K A027099 nonn
%O A027099 0,2
%A A027099 _Clark Kimberling_
%E A027099 Title corrected by _Sean A. Irvine_, Oct 23 2019