login
A059091
Numbers k such that 3*7^k - 2 is prime.
1
1, 11, 168, 185, 467, 767, 1400, 1428, 1736, 2516, 3275, 3540, 51156
OFFSET
1,2
COMMENTS
a(13) > 37584. - Jinyuan Wang, Jan 21 2020
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
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 12 2001
EXTENSIONS
a(13) from Michael S. Branicky, Jul 09 2024
STATUS
approved