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 A027317 #9 Oct 27 2019 19:55:59
%S A027317 1,6,71,561,4797,41462,359530,3124752,27213084,237432807,2075064759,
%T A027317 18162872365,159198909233,1397157808149,12275908402205,
%U A027317 107974903916703,950639462501475,8377212510209165,73882962176311701,652114141845864819,5759883148706408695
%N A027317 a(n) = Sum_{k=0..m-2} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.
%K A027317 nonn
%O A027317 2,2
%A A027317 _Clark Kimberling_
%E A027317 More terms from _Sean A. Irvine_, Oct 27 2019