OFFSET
1,1
COMMENTS
The corresponding primes are in A376223.
EXAMPLE
39 is a term because the 3 first divisors of 39 are {1,3,13} and 1^1 + 3^2 + 13^3 = 2207 is prime.
189 is a term since the 7 first divisors of 189 are {1, 3, 7, 9, 21, 27, 63} and 1^1+3^2+7^3+9^4+21^5+27^6+63^7 = 3939372150671 is prime.
MAPLE
with(numtheory):nn:=1700:
for n from 1 to nn do:
d:=divisors(n):n0:=nops(d):s:=sum(âd[k]^kâ, âkâ=1..n0-1):
if isprime(s)
then
printf(`%d, `, n):
else
fi:
od:
MATHEMATICA
Select[Range[1700], PrimeQ[Sum[Part[Divisors[#], i]^i, {i, DivisorSigma[0, #]-1}]] &] (* Stefano Spezia, Sep 16 2024 *)
PROG
(PARI) isok(k) = my(d=divisors(k)); isprime(sum(j=1, #d-1, d[j]^j)); \\ Michel Marcus, Sep 16 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Sep 16 2024
STATUS
approved