A345402 Numbers k such that (42^k-1)/41 is prime.

2, 1319, 337081

Offset: 1

Author

Paul Bourdelais, Sep 28 2021

Keywords

• nonn
• hard
• more
• bref

Comments

These are the repunit primes in base 42.

Examples

			2 is a member since (42^2-1)/41 = 43 is prime.
		

Links

• P. Bourdelais, A Generalized Repunit Conjecture

Crossrefs

Cf. A218745.

Programs

Mathematica

Do[ If[ PrimeQ[ (42^n-1)/41], Print[n]], {n, 2, 400000}]

PARI

is(n)=isprime((42^n-1)/41)