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A059748
Numbers k such that 5*2^k + 7 is prime.
1
1, 3, 5, 7, 11, 15, 19, 21, 31, 37, 47, 51, 59, 109, 163, 199, 221, 659, 709, 1795, 2525, 3103, 6139, 7887, 13699, 18255, 19469, 22741, 23311, 59141, 98291, 134893
OFFSET
1,2
COMMENTS
Next term > 29815. - Jinyuan Wang, Feb 02 2020
MATHEMATICA
Do[ If[ PrimeQ[ 5*2^n + 7 ], Print[n] ], {n, 1, 3000} ]
Select[Range[0, 8000], PrimeQ[(5*2^# + 7)] &] (* Vincenzo Librandi, Sep 29 2012 *)
PROG
(PARI) is(n)=ispseudoprime(5*2^n+7) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A059749 (5*2^k - 7 is prime).
Sequence in context: A351695 A190812 A238738 * A122124 A219655 A335039
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 10 2001
EXTENSIONS
a(22)-a(24) from Vincenzo Librandi, Sep 29 2012
a(25)-a(29) from Jinyuan Wang, Feb 02 2020
a(30) from Michael S. Branicky, May 19 2023
a(31)-a(32) from Michael S. Branicky, Jul 27 2024
STATUS
approved