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 A048784 a(n) = tau(binomial(2*n,n)), where tau = number of divisors (A000005). 5

%I

%S 1,2,4,6,8,18,24,32,48,48,48,128,96,192,384,480,384,768,1152,1536,

%T 2304,2048,2048,3840,3456,4608,6144,3840,8192,20480,10240,12288,18432,

%U 36864,36864,49152,24576,32768,98304,92160,73728,245760,262144

%N a(n) = tau(binomial(2*n,n)), where tau = number of divisors (A000005).

%H Charles R Greathouse IV, <a href="/A048784/b048784.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = A000005(A000984(n)). - _Michel Marcus_, Aug 21 2013

%t f[n_] := DivisorSigma[0, Binomial[2 n, n]]; Table[f@n, {n, 0, 42}] (* _Robert G. Wilson v_, Apr 08 2009 *)

%o (PARI) fv(n,p)=my(s);while(n\=p,s+=n);s

%o a(n)=my(s=1);forprime(p=2,2*n,s*=fv(2*n,p)-2*fv(n,p)+1);s \\ _Charles R Greathouse IV_, Aug 21 2013

%K nonn

%O 0,2

%A _David Johnson-Davies_

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Last modified August 3 22:03 EDT 2021. Contains 346441 sequences. (Running on oeis4.)