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 A027236 #8 Oct 27 2019 11:34:22
%S A027236 1,3,8,23,55,149,339,889,1966,5059,10985,27939,59898,151210,321155,
%T A027236 806806,1701347,4260511,8933737,22325426,46600476,116300505,241846731,
%U A027236 603086027,1250175771,3116094702,6442311137,16054097455,33114584924
%N A027236 a(n) = Sum_{k=0..n} (k+1) * A026758(n, n-k).
%K A027236 nonn
%O A027236 0,2
%A A027236 _Clark Kimberling_