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 A027280 #8 Oct 26 2019 22:49:51
%S A027280 26,164,1224,7664,51488,326456,2126376,13574046,87554326,560845908,
%T A027280 3607790136,23158545126,148945375022,957564479960,6162874994108,
%U A027280 39672627184498,255578754020002,1647166273816172,10622076015026288,68529892093271816,442357250742603624
%N A027280 a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026568.
%K A027280 nonn
%O A027280 3,1
%A A027280 _Clark Kimberling_
%E A027280 More terms from _Sean A. Irvine_, Oct 26 2019