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A032409
Numbers k such that 119*2^k + 1 is prime.
0
1, 3, 7, 13, 21, 23, 45, 63, 553, 1115, 2471, 2773, 7363, 25767, 26265, 32445, 41291, 55583, 113637, 376951, 787017, 858427, 915371, 1242207, 1759247, 3161195
OFFSET
1,2
MATHEMATICA
Select[Range[1000], PrimeQ[119*2^# + 1] & ] (* Robert Price, Dec 17 2018 *)
PROG
(PARI) is(n)=ispseudoprime(119*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A169633 A069194 A100531 * A073896 A299478 A355310
KEYWORD
nonn,more
EXTENSIONS
Extended by Hugo Pfoertner, Jul 02 2003
a(20)-a(25) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 17 2018
a(26) from Jeppe Stig Nielsen, Jan 15 2022
STATUS
approved