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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 (list; graph; refs; listen; history; text; internal format)
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: A345166 A277006 A220355 * A129128 A164922 A205523

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

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Last modified December 2 22:46 EST 2021. Contains 349445 sequences. (Running on oeis4.)