OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
9^9 = (3^2)^9 = 3^18 has 19 = 19^1 divisors, so 9 is a term.
10^10 = 2^10 * 5^10 has 121 = 11^2 divisors, so 10 is a term.
11^11 has 12 = 2^2 * 3^1 divisors, so 11 is not a term.
MATHEMATICA
a={}; For[k=1, k<600, k++, If[PrimePowerQ[DivisorSigma[0, k^k]], AppendTo[a, k]]]; a (* Stefano Spezia, Jun 02 2021 *)
Select[Range[600], PrimePowerQ[DivisorSigma[0, #^#]]&] (* Harvey P. Dale, Oct 29 2022 *)
PROG
(PARI) isok(k) = isprimepower(numdiv(k^k)); \\ Michel Marcus, Jun 02 2021
(Python)
from functools import reduce
from operator import mul
from sympy import factorint
A343732_list = [n for n in range(2, 10**3) if len(factorint(reduce(mul, (n*d+1 for d in factorint(n).values())))) == 1] # Chai Wah Wu, Jun 03 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Jon E. Schoenfield, Jun 01 2021
STATUS
approved