OFFSET
1,1
COMMENTS
These are the repunit primes in base 42.
LINKS
P. Bourdelais, A Generalized Repunit Conjecture
EXAMPLE
2 is a member since (42^2-1)/41 = 43 is prime.
MATHEMATICA
Do[ If[ PrimeQ[ (42^n-1)/41], Print[n]], {n, 2, 400000}]
PROG
(PARI) is(n)=isprime((42^n-1)/41)
CROSSREFS
KEYWORD
nonn,hard,more,bref
AUTHOR
Paul Bourdelais, Sep 28 2021
STATUS
approved