login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034974 Number of divisors of binomial(n, floor(n/2)), the terms of A001405. 12
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 2 22:24 EDT 2020. Contains 333194 sequences. (Running on oeis4.)