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 A026967 #10 Oct 20 2019 16:28:54
%S A026967 1,4,24,90,365,1376,5272,20098,77016,295836,1139834,4402490,17042341,
%T A026967 66101848,256838544,999512058,3895191476,15199297796,59377405654,
%U A026967 232208188726,908978576496,3561356276424,13964734085774,54799750800530,215193550759630,845596666261036
%N A026967 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026637.
%K A026967 nonn
%O A026967 1,2
%A A026967 _Clark Kimberling_
%E A026967 More terms from _Sean A. Irvine_, Oct 20 2019