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A048784 a(n) = tau(binomial(2*n,n)), where tau = number of divisors (A000005). 4
1, 2, 4, 6, 8, 18, 24, 32, 48, 48, 48, 128, 96, 192, 384, 480, 384, 768, 1152, 1536, 2304, 2048, 2048, 3840, 3456, 4608, 6144, 3840, 8192, 20480, 10240, 12288, 18432, 36864, 36864, 49152, 24576, 32768, 98304, 92160, 73728, 245760, 262144 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = A000005(A000984(n)). - Michel Marcus, Aug 21 2013

MATHEMATICA

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

PROG

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

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

CROSSREFS

Sequence in context: A100055 A304660 A104001 * A152491 A133296 A323333

Adjacent sequences:  A048781 A048782 A048783 * A048785 A048786 A048787

KEYWORD

nonn

AUTHOR

David Johnson-Davies

STATUS

approved

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Last modified June 25 11:56 EDT 2019. Contains 324352 sequences. (Running on oeis4.)