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A050854
Numbers n such that 205*2^n-1 is prime.
0
1, 9, 39, 45, 49, 67, 75, 99, 129, 159, 177, 445, 721, 771, 829, 849, 865, 1971, 3045, 8397, 9019, 10749, 21037, 30529, 38349, 46257, 53577, 64695, 77451, 128019, 420297, 462261
OFFSET
1,2
PROG
(PARI) is(n)=ispseudoprime(205*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A071238 A213583 A343521 * A053181 A348545 A346950
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