A068903 Binomial(tau(n),omega(n)), where tau(n) is the number of divisors of n (A000005) and omega the number of distinct prime factors (A001221).

1, 2, 2, 3, 2, 6, 2, 4, 3, 6, 2, 15, 2, 6, 6, 5, 2, 15, 2, 15, 6, 6, 2, 28, 3, 6, 4, 15, 2, 56, 2, 6, 6, 6, 6, 36, 2, 6, 6, 28, 2, 56, 2, 15, 15, 6, 2, 45, 3, 15, 6, 15, 2, 28, 6, 28, 6, 6, 2, 220, 2, 6, 15, 7, 6, 56, 2, 15, 6, 56, 2, 66, 2, 6, 15, 15, 6, 56

Offset: 1

Author

Reinhard Zumkeller, Mar 06 2002

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A068904, A068905.

Programs

Mathematica

Table[Binomial[DivisorSigma[0,n],PrimeNu[n]],{n,100}] (* Harvey P. Dale, Oct 17 2016 *)

PARI

a(n) = binomial(numdiv(n), omega(n)); \\ Michel Marcus, Apr 23 2017

Extensions

More terms from Harvey P. Dale, Oct 17 2016