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A058595 Numbers k such that 7*2^k + 5 is prime. 1
1, 3, 5, 11, 13, 61, 115, 653, 889, 957, 997, 1013, 1421, 2329, 2675, 4795, 5755, 7059, 7405, 7613, 7973, 9445, 23467 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(24) > 30000. - Jinyuan Wang, Feb 01 2020

LINKS

Table of n, a(n) for n=1..23.

MATHEMATICA

Do[ If[ PrimeQ[ 7*2^n + 5 ], Print[ n ] ], {n, 1, 6800} ]

Select[Range[0, 10000], PrimeQ[(7*2^# + 5)] &] (* Vincenzo Librandi, Sep 29 2012 *)

PROG

(PARI) is(n)=ispseudoprime(7*2^n+5) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A058602 (7*2^k - 5 is prime).

Sequence in context: A162876 A162875 A166564 * A154773 A176658 A086284

Adjacent sequences:  A058592 A058593 A058594 * A058596 A058597 A058598

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Dec 26 2000

EXTENSIONS

a(18)-a(22) from Vincenzo Librandi, Sep 29 2012

a(23) from Jinyuan Wang, Feb 01 2020

STATUS

approved

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Last modified August 12 23:19 EDT 2020. Contains 336440 sequences. (Running on oeis4.)