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A156125 a(n)=10^n*C(2n,n)/C(n+3,3). 1

%I #6 Mar 30 2022 19:30:31

%S 1,5,60,1000,20000,450000,11000000,286000000,7800000000,221000000000,

%T 6460000000000,193800000000000,5943200000000000,185725000000000000,

%U 5899500000000000000,190095000000000000000,6203100000000000000000

%N a(n)=10^n*C(2n,n)/C(n+3,3).

%C Hankel transform is 10^(n^2-1+0^n)*A156126(n).

%F G.f.: F(1/2,1;4;40x);

%F a(n)=6*10^n*A000108(n)/((n+2)(n+3))=10^(n-1)*A007272(n).

%F (n+3)*a(n) +20*(1-2*n)*a(n-1)=0. - _R. J. Mathar_, Oct 25 2012

%t Table[10^n Binomial[2n,n]/Binomial[n+3,3],{n,0,20}] (* _Harvey P. Dale_, Mar 30 2022 *)

%K easy,nonn

%O 0,2

%A _Paul Barry_, Feb 04 2009

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Last modified September 19 17:13 EDT 2024. Contains 376014 sequences. (Running on oeis4.)