A122004 Primes p that divide A123373(p-1).

2, 3, 5, 23, 29

Offset

1,1

Links

Table of n, a(n) for n=1..5.

Example

A123373 begins {4, 48, 3598, 924780, 287358579128, ...}.
a(1) = 2 because 2 divides A123373(1) = 4.
a(2) = 3 because 3 divides A123373(2) = 48.
a(3) = 5 because 5 divides A123373(4) = 924780.

Prog

(PARI) is(p) = isprime(p) && sum(j=1, p-1, sum(k=1, p-1, Mod(prime(k), p)^prime(j))) == 0; \\ Jinyuan Wang, Jan 16 2021
(Python)
from sympy import nextprime, prime
p, A122004_list = 2, []
while p < 10**6:
    if 0 == sum(pow(prime(i), prime(j), p) for i in range(1, p) for j in range(1, p)) % p:
        A122004_list.append(p)
    p = nextprime(p) # Chai Wah Wu, Feb 19 2021

Crossrefs

Cf. A086787, A123373.

Sequence in context: A024767 A041195 A042141 * A023231 A034470 A237812

Adjacent sequences: A122001 A122002 A122003 * A122005 A122006 A122007

Keyword

nonn,more,hard

Author

Alexander Adamchuk, Oct 14 2006

Status

approved