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A064144
a(n) is the number of divisors of n!+1.
5
2, 2, 2, 3, 3, 4, 3, 4, 8, 4, 2, 6, 4, 4, 8, 32, 8, 64, 4, 4, 8, 8, 12, 4, 4, 4, 2, 4, 8, 32, 16, 16, 32, 4, 32, 64, 2, 4, 16, 128, 2, 8, 16, 8, 8, 8, 16, 4, 32, 32, 64, 16, 16, 4, 4, 16, 8, 16, 4, 16, 16, 8, 32, 8
OFFSET
1,1
LINKS
William Gerst, A conjecture on the prime factorization of n!+1, arXiv:1809.07360 [math.GM], 2018.
FORMULA
a(n) = tau(n!+1).
MATHEMATICA
Do[ Print[ DivisorSigma[0, n! + 1]], {n, 1, 40} ]
PROG
(PARI) a(n) = numdiv(n! + 1); \\ Harry J. Smith, Sep 09 2009
(Python)
from math import factorial
from sympy import divisor_count
def A064144(n): return divisor_count(factorial(n)+1) # Chai Wah Wu, Oct 20 2023
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Sep 11 2001
EXTENSIONS
More terms from Robert G. Wilson v, Oct 04 2001
a(42)-a(64) from Harry J. Smith, Sep 09 2009
Edited by Jon E. Schoenfield, Jun 21 2018
STATUS
approved