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

1,2

Links

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

Formula

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

Example

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

Mathematica

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

Prog

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

Crossrefs

Cf. A001405, A034973.

Sequence in context: A023817 A300754 A145392 * A048275 A211508 A109874

Adjacent sequences: A034971 A034972 A034973 * A034975 A034976 A034977

Keyword

nonn

Author

Labos Elemer

Status

approved