

A309410


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


0




OFFSET

1,1


COMMENTS

Larger terms correspond to probable primes.


LINKS

Table of n, a(n) for n=1..3.
P. Bourdelais, A Generalized Repunit Conjecture


MATHEMATICA

Do[p=Prime[n]; If[ PrimeQ[(41^p + 1)/42], Print[p]], {n, 1, 1000000}]


PROG

(PARI) is(n)=ispseudoprime((41^n+1)/42)


CROSSREFS

Sequence in context: A012157 A012137 A171198 * A201311 A012182 A012029
Adjacent sequences: A309407 A309408 A309409 * A309411 A309412 A309413


KEYWORD

nonn,bref,hard,more


AUTHOR

Paul Bourdelais, Jul 29 2019


STATUS

approved



