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 A127128 #9 Jan 28 2020 12:08:30
%S A127128 1,2,9,54,412,3834,42131,533558,7645065,122177706,2153221318,
%T A127128 41464853266,865908079369,19484990264956,469910189792853,
%U A127128 12089047867952058,330423404118495975,9561012695542004496
%N A127128 Column 1 of triangle A127126.
%C A127128 Convolution square of A127131.
%H A127128 G. C. Greubel, <a href="/A127128/b127128.txt">Table of n, a(n) for n = 1..80</a>
%t A127128 T[n_, k_]:= T[n, k]= If[k==n, 1, Coefficient[(1 +x*Sum[x^(r-k-1)*Sum[T[r, c], {c,k+1,r}], {r,k+1,n}] + x^(n+1))^(k+1), x, n-k]]; Table[T[n, 1], {n, 1, 20}] (* _G. C. Greubel_, Jan 28 2020 *)
%Y A127128 Cf. A127126; A127131; other columns: A127127, A127129, A127130.
%K A127128 nonn
%O A127128 1,2
%A A127128 _Paul D. Hanna_, Jan 05 2007