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 A027303 #11 Jan 03 2024 06:29:37
%S A027303 2,5,34,98,496,1545,7010,22924,98636,333463,1393014,4824350,19795200,
%T A027303 69818507,283195638,1013208668,4078132240,14758843463,59087809638,
%U A027303 215859015800,860951003152,3169965920150,12609168181324,46735070397768,185532421441976,691582241867227
%N A027303 a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+2), with T given by A008315.
%K A027303 nonn
%O A027303 3,1
%A A027303 _Clark Kimberling_
%E A027303 More terms from _Sean A. Irvine_, Oct 26 2019