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 A027242 #8 Oct 26 2019 15:34:00
%S A027242 1,10,68,402,2258,12072,64963,338824,1817063,9467940,51258781,
%T A027242 269085042,1475551064,7822940886,43422818989,232480179882,
%U A027242 1303561020575,7040175844640,39786449049369,216469879238194,1230485470688864,6736096483008440,38451562317699992,211571284685596944
%N A027242 a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026769.
%K A027242 nonn
%O A027242 3,2
%A A027242 _Clark Kimberling_
%E A027242 More terms from _Sean A. Irvine_, Oct 26 2019