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

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

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

Maple

A048784 := proc(n)
    numtheory[tau](binomial(2*n, n)) ;
end proc:
seq(A048784(n), n=0..30) ; # R. J. Mathar, Jul 12 2024

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: A304660 A344902 A104001 * A152491 A355557 A329738

Adjacent sequences: A048781 A048782 A048783 * A048785 A048786 A048787

Keyword

nonn

Author

David Johnson-Davies

Status

approved