A034974 Number of divisors of binomial(n, floor(n/2)), the terms of A001405.

1, 2, 2, 4, 4, 6, 4, 8, 12, 18, 16, 24, 24, 32, 24, 48, 32, 48, 32, 48, 96, 128, 64, 96, 144, 192, 288, 384, 384, 480, 192, 384, 512, 768, 768, 1152, 1152, 1536, 1536, 2304, 1536, 2048, 1536, 2048, 3072, 3840, 2304, 3456, 3456, 4608, 4608, 6144, 3072, 3840, 6144

Offset: 1

Author

Labos Elemer

Keywords

• nonn

Examples

			a(59) = d(C(59,29)) = d(59132290782430712) = 8192 = 4*2^11.
		

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A001405, A034973.

Programs

Mathematica

Table[DivisorSigma[0,Binomial[n,Floor[n/2]]],{n,60}] (* Harvey P. Dale, Jun 12 2012 *)

PARI

a(n) = numdiv(binomial(n, n\2)); \\ Michel Marcus, Feb 25 2014

Formula

a(n) = A000005(A001405(n)). - Michel Marcus, Feb 25 2014