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 A127134 #6 Jan 28 2020 15:19:06
%S A127134 1,2,18,284,6680,211398,8439235,407247048,23056215138,1498169721930,
%T A127134 109876657252604,8976437481923520,808257688877060396,
%U A127134 79516093326076500590,8485004019719253675540,976009472808194554659440
%N A127134 Central terms of triangle A127126; a(n) = A127126(2n,n).
%C A127134 a(n) is divisible by (n+1): a(n)/(n+1) = A127135(n).
%H A127134 G. C. Greubel, <a href="/A127134/b127134.txt">Table of n, a(n) for n = 0..50</a>
%t A127134 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,0,20}] (* _G. C. Greubel_, Jan 28 2020 *)
%Y A127134 Cf. A127126, A127127, A127128, A127129, A127130, A127131, A127132, A127133, A127135.
%K A127134 nonn
%O A127134 0,2
%A A127134 _Paul D. Hanna_, Jan 05 2007