A059041 Numbers k such that 3*7^k + 2 is prime.

0, 1, 2, 3, 5, 6, 7, 10, 39, 99, 115, 158, 697, 966, 2602, 2899, 4057, 5226, 8279, 17946

Offset

1,3

Comments

a(21) > 20000. - Jinyuan Wang, Dec 14 2019

Links

Table of n, a(n) for n=1..20.

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

Adjacent sequences: A059038 A059039 A059040 * A059042 A059043 A059044

Keyword

nonn,more

Author

Robert G. Wilson v, Feb 12 2001

Extensions

a(19)-a(20) from Jinyuan Wang, Dec 14 2019

Status

approved