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A059077 Numbers k such that 2*7^k - 3 is prime. 0
1, 3, 4, 7, 132, 253, 9040, 21888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(9) > 27376. - Jinyuan Wang, Dec 21 2019

LINKS

Table of n, a(n) for n=1..8.

MATHEMATICA

Do[ If[ PrimeQ[ 2*7^n - 3 ], Print[n] ], {n, 1, 6000} ]

PROG

(PARI) is(n)=ispseudoprime(2*7^n-3) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

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

Sequence in context: A042543 A041987 A100978 * A042707 A229348 A215758

Adjacent sequences:  A059074 A059075 A059076 * A059078 A059079 A059080

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Feb 12 2001

EXTENSIONS

a(7)-a(8) from Jinyuan Wang, Dec 21 2019

STATUS

approved

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Last modified July 16 13:35 EDT 2020. Contains 335788 sequences. (Running on oeis4.)