A172443 Numbers with exactly 64 divisors.

7560, 9240, 10920, 11880, 13440, 14040, 14280, 15960, 16632, 17160, 17280, 18360, 19320, 19656, 20520, 20790, 21000, 21120, 22440, 24024, 24192, 24360, 24570, 24840, 24960, 25080, 25704, 26040, 26520, 27000, 28728, 29568, 29640, 30030, 30360, 30888, 31080

Offset

1,1

Comments

The first squarefree term of this sequence is the primorial a(34) = 30030.

Almost all terms of this sequence (in the sense of having relative density 1) are squarefree, that is in our case, the product of six distinct primes = A067885. - Charles R Greathouse IV, Aug 27 2021

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

10920 has 64 divisors.

Mathematica

Select[Range[100000], DivisorSigma[0, #]==64&]

Prog

(PARI) is(n) = numdiv(n) == 64 \\ David A. Corneth, Aug 27 2021
(Python)
from sympy import divisor_count
def ok(n): return divisor_count(n) == 64
print(list(filter(ok, range(31100)))) # Michael S. Branicky, Aug 27 2021

Crossrefs

Cf. A067885.

Sequence in context: A210171 A234987 A157322 * A190108 A308913 A145313

Adjacent sequences: A172440 A172441 A172442 * A172444 A172445 A172446

Keyword

nonn,easy

Author

Harvey P. Dale, Nov 20 2010

Status

approved