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 A156125 #6 Mar 30 2022 19:30:31
%S A156125 1,5,60,1000,20000,450000,11000000,286000000,7800000000,221000000000,
%T A156125 6460000000000,193800000000000,5943200000000000,185725000000000000,
%U A156125 5899500000000000000,190095000000000000000,6203100000000000000000
%N A156125 a(n)=10^n*C(2n,n)/C(n+3,3).
%C A156125 Hankel transform is 10^(n^2-1+0^n)*A156126(n).
%F A156125 G.f.: F(1/2,1;4;40x);
%F A156125 a(n)=6*10^n*A000108(n)/((n+2)(n+3))=10^(n-1)*A007272(n).
%F A156125 (n+3)*a(n) +20*(1-2*n)*a(n-1)=0. - _R. J. Mathar_, Oct 25 2012
%t A156125 Table[10^n Binomial[2n,n]/Binomial[n+3,3],{n,0,20}] (* _Harvey P. Dale_, Mar 30 2022 *)
%K A156125 easy,nonn
%O A156125 0,2
%A A156125 _Paul Barry_, Feb 04 2009