A175748 Numbers with 39 divisors.

36864, 102400, 200704, 495616, 692224, 1183744, 1478656, 2125764, 2166784, 3444736, 3936256, 5607424, 6885376, 7573504, 9048064, 11505664, 13286025, 14258176, 15241216, 18386944, 20647936, 21827584, 25563136, 26040609, 28217344, 32444416, 38539264, 41783296

Offset

1,1

Comments

Numbers of the forms p^38 and p^12*q^2, where p and q are distinct primes.

Links

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

OEIS Wiki, Index entries for number of divisors

Formula

A000005(a(n)) = 39.

Sum_{n>=1} 1/a(n) = P(2)*P(12) - P(14) + P(38) = 0.0000500204..., where P is the prime zeta function. - Amiram Eldar, Jul 03 2022

Mathematica

Select[Range[7000000], DivisorSigma[0, #]==39&] (* Vladimir Joseph Stephan Orlovsky, May 06 2011 *)

Prog

(PARI) is(n)=numdiv(n)==39 \\ Charles R Greathouse IV, Jun 19 2016

Crossrefs

Cf. A000005, A139572, A175747.

Sequence in context: A212467 A187032 A251386 * A204104 A229509 A223304

Adjacent sequences: A175745 A175746 A175747 * A175749 A175750 A175751

Keyword

nonn

Author

Jaroslav Krizek, Aug 27 2010

Extensions

Extended by T. D. Noe, May 08 2011

Status

approved