A366758 a(n) is the sum of the divisors of n!+1.

3, 3, 4, 8, 31, 133, 832, 5113, 41044, 388800, 3958704, 39916802, 518682390, 6302045232, 90968651712, 1332614649600, 22844265373440, 356226551466344, 7504470340300800, 123358411682195904, 2432902126073962432, 52279222588118377280, 1175121515279802150144

Offset: 0

Author

Sean A. Irvine, Oct 20 2023

Keywords

• nonn

Examples

			a(5) = 133 because the divisors of 5!+1 are {1, 11, 121}.
		

Crossrefs

Cf. A038507, A000203, A064144, A062569, A366757.

Programs

Maple

a:=n->numtheory[sigma](n!+1):
seq(a(n), n=0..30);

Mathematica

DivisorSigma[1,Range[0,25]!+1] (* Paolo Xausa, Oct 21 2023 *)

Python

from math import factorial
from sympy import divisor_sigma
def A366758(n): return divisor_sigma(factorial(n)+1) # Chai Wah Wu, Oct 20 2023

Formula

a(n) = sigma(n!+1) = A000203(A038507(n)).