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 A027297 #9 Oct 27 2019 11:13:49
%S A027297 1,4,30,104,567,1952,9453,32900,150029,528956,2327156,8303216,
%T A027297 35679835,128633440,543723257,1977821700,8260172309,30278441400,
%U A027297 125314192728,462409521376,1900445030538,7053236494784,28828752666375,107536008386924,437602449724101
%N A027297 a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+3), with T given by A026022.
%K A027297 nonn
%O A027297 3,2
%A A027297 _Clark Kimberling_
%E A027297 More terms from _Sean A. Irvine_, Oct 26 2019