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A112245
Numbers k such that 65537*2^k+1 is prime.
1
287, 1695, 81359, 512895
OFFSET
1,1
COMMENTS
Note that 65537=2^16+1 is the largest known Fermat prime. These n yield provable primes. The primes are the smallest numbers in classes 303, 1711 and 81375 of the phi iteration (see A007755).
Jacques Molne found 512895. The corresponding provable prime is the smallest number in class 512911 of the Phi iteration.
PROG
(PARI) is(n)=ispseudoprime(65537*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A002253, A002254, A002259, A053345 (F*2^n+1 is prime, where F is a Fermat prime).
Sequence in context: A158252 A236869 A158287 * A289339 A011817 A334008
KEYWORD
nonn,hard
AUTHOR
T. D. Noe, Aug 30 2005, Aug 26 2007
STATUS
approved