login
A309410
Numbers k such that (41^k + 1)/42 is prime.
0
17, 691, 113749
OFFSET
1,1
COMMENTS
Larger terms correspond to probable primes.
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
KEYWORD
nonn,bref,hard,more
AUTHOR
Paul Bourdelais, Jul 29 2019
STATUS
approved