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A050882
Numbers n such that 247*2^n-1 is prime.
0
133, 277, 805, 2341, 68845, 952069
OFFSET
1,1
PROG
(PARI) is(n)=ispseudoprime(247*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A316630 A250766 A254692 * A146233 A146181 A105984
KEYWORD
hard,nonn
AUTHOR
N. J. A. Sloane, Dec 29 1999
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
STATUS
approved