OFFSET
1,2
COMMENTS
Corresponding values of sigma(m): 1, 24, 24, 40320, 40320, 40320, 40320, 40320, 40320, 40320, 40320, 40320, ...
Corresponding values of tau(m): 1, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, ...
EXAMPLE
sigma(14) = 24 = tau(14)! = 4!.
MATHEMATICA
Select[Range[40000], DivisorSigma[1, #] == DivisorSigma[0, #]! &] (* Amiram Eldar, Feb 22 2022 *)
PROG
(Magma) [m: m in [1..5*10^6] | &+Divisors(m) eq Factorial(#Divisors(m))]
(PARI) isok(m) = my(f=factor(m)); sigma(f) == numdiv(f)!; \\ Michel Marcus, Feb 23 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Feb 22 2022
EXTENSIONS
a(37)-a(38) from Amiram Eldar, Feb 22 2022
STATUS
approved