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 A027250 #9 Oct 26 2019 15:35:28
%S A027250 1,12,95,639,3917,23377,132553,762434,4201955,23901906,130453555,
%T A027250 740755012,4035754137,22952934073,125259143235,714206660342,
%U A027250 3909459844469,22346990842402,122748276118411,703146926077588,3875572768594421,22238537172443007,122969745150601115
%N A027250 a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026780.
%K A027250 nonn
%O A027250 3,2
%A A027250 _Clark Kimberling_
%E A027250 More terms from _Sean A. Irvine_, Oct 26 2019