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A032419
Numbers k such that 139*2^k + 1 is prime.
1
2, 14, 914, 12614, 335522, 1567874
OFFSET
1,1
MAPLE
select(k->isprime(139*2^k+1), [$0..1000])[]; # Muniru A Asiru, Dec 18 2018
MATHEMATICA
Select[Range[1000], PrimeQ[139*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)
PROG
(PARI) is(n)=ispseudoprime(139*2^n+1) \\ Charles R Greathouse IV, Jun 07 2017
CROSSREFS
KEYWORD
nonn,hard,more
EXTENSIONS
One more term (from the Ballinger-Keller web page) from M. F. Hasler, Apr 18 2007
a(6) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
STATUS
approved