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 A026948 #9 Oct 18 2019 04:03:17
%S A026948 1,8,58,272,1770,7428,46928,189808,1185645,4724160,29362806,116207424,
%T A026948 720606705,2842936320,17610412600,69378730880,429579843435,
%U A026948 1691519468760,10472653252550,41235710124400,255326054688320,1005560117623204,6227515552731528,24534901740913872
%N A026948 a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026374.
%K A026948 nonn
%O A026948 2,2
%A A026948 _Clark Kimberling_
%E A026948 More terms from _Sean A. Irvine_, Oct 17 2019