A059091 Numbers k such that 3*7^k - 2 is prime.

1, 11, 168, 185, 467, 767, 1400, 1428, 1736, 2516, 3275, 3540

Offset

1,2

Comments

a(13) > 37584. - Jinyuan Wang, Jan 21 2020

Links

Table of n, a(n) for n=1..12.

Mathematica

Do[ If[ PrimeQ[ 3*7^n - 2 ], Print[n] ], {n, 1, 5000} ]

Prog

(PARI) is(n)=ispseudoprime(3*7^n-2) \\ Charles R Greathouse IV, Jun 13 2017
(Magma) [k: k in [0..1000] | IsPrime(3*7^k-2)]; // Jinyuan Wang, Jan 21 2020

Crossrefs

Cf. A059041 (3*7^k+2 is prime).

Sequence in context: A088293 A145559 A159968 * A255971 A157944 A362501

Adjacent sequences: A059088 A059089 A059090 * A059092 A059093 A059094

Keyword

nonn,more

Author

Robert G. Wilson v, Feb 12 2001

Status

approved