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 A127135 #6 Jan 28 2020 16:11:34
%S A127135 1,1,6,71,1336,35233,1205605,50905881,2561801682,149816972193,
%T A127135 9988787022964,748036456826960,62173668375158492,5679720951862607185,
%U A127135 565666934647950245036,61000592050512159666215
%N A127135 Derived from the central terms (A127134) of triangle A127126; a(n) = A127126(2n,n)/(n+1).
%H A127135 G. C. Greubel, <a href="/A127135/b127135.txt">Table of n, a(n) for n = 0..50</a>
%F A127135 a(n) = A127134(n)/(n+1).
%t A127135 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[2*n, n]/(n+1), {n, 0, 20}] (* _G. C. Greubel_, Jan 28 2020 *)
%Y A127135 Cf. A127126, A127127, A127128, A127129, A127130, A127131, A127132, A127133, A127134.
%K A127135 nonn
%O A127135 0,3
%A A127135 _Paul D. Hanna_, Jan 05 2007