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A059041
Numbers k such that 3*7^k + 2 is prime.
2
0, 1, 2, 3, 5, 6, 7, 10, 39, 99, 115, 158, 697, 966, 2602, 2899, 4057, 5226, 8279, 17946, 44850
OFFSET
1,3
COMMENTS
a(21) > 20000. - Jinyuan Wang, Dec 14 2019
a(22) > 60000. - Michael S. Branicky, Jul 08 2024
MATHEMATICA
Do[ If[ PrimeQ[ 3*7^n + 2 ], Print[n] ], {n, 1, 6000} ]
PROG
(PARI) is(n)=ispseudoprime(3*7^n+2) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A059091 (3*7^k-2 is prime).
Sequence in context: A277006 A220355 A353954 * A129128 A355647 A367585
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 12 2001
EXTENSIONS
a(19)-a(20) from Jinyuan Wang, Dec 14 2019
a(21) from Michael S. Branicky, Jul 07 2024
STATUS
approved