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A050590
Numbers k such that 129*2^k-1 is prime.
0
1, 3, 4, 5, 8, 9, 12, 16, 28, 51, 56, 59, 72, 73, 88, 93, 105, 148, 165, 292, 368, 445, 635, 771, 773, 940, 1173, 1965, 2661, 3092, 5001, 5091, 8741, 9773, 13960, 15328, 19408, 19911, 21228, 34876, 37341, 38564, 39055, 39152, 45395, 68825, 72360, 78365, 126303, 130240, 150808, 214985
OFFSET
1,2
MATHEMATICA
Select[Range[1000], PrimeQ[129*2^# - 1] & ] (* Robert Price, Dec 23 2018 *)
PROG
(PARI) is(n)=ispseudoprime(129*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A316976 A256173 A050070 * A329856 A327984 A066906
KEYWORD
hard,nonn
AUTHOR
N. J. A. Sloane, Dec 29 1999
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
a(49)-a(52) from the Wilfrid Keller link by Robert Price, Dec 23 2018
STATUS
approved