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 A027292 #8 Oct 26 2019 23:09:18
%S A027292 1,3,8,12,31,48,121,192,475,768,1872,3072,7398,12288,29295,49152,
%T A027292 116179,196608,461284,786432,1833202,3145728,7290818,12582912,
%U A027292 29014046,50331648,115521296,201326592,460153644,805306368,1833594171
%N A027292 a(n) = Sum_{k=0..m} (k+1) * A026009(n, m-k) where m = floor(n/2)+1.
%K A027292 nonn
%O A027292 0,2
%A A027292 _Clark Kimberling_