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 A027226 #9 Oct 25 2019 04:58:24
%S A027226 1,11,75,496,2523,14903,68478,389040,1705001,9552071,40792260,
%T A027226 227758442,957346363,5353798598,22267534284,125033595506,516148089100,
%U A027226 2913354375795,11958933491775,67884893610121,277431526202759,1583886793301326,6449958580342975,37029044240499120
%N A027226 a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026747.
%K A027226 nonn
%O A027226 3,2
%A A027226 _Clark Kimberling_
%E A027226 More terms from _Sean A. Irvine_, Oct 24 2019