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A050846
Numbers k such that 189*2^k-1 is prime.
1
3, 4, 5, 8, 11, 12, 24, 33, 44, 48, 56, 76, 93, 108, 172, 216, 304, 363, 401, 420, 500, 545, 581, 756, 875, 1552, 1931, 2740, 2787, 2825, 3443, 5235, 8444, 10523, 12755, 14585, 21161, 24404, 25880, 31316, 31965, 32040, 34233, 34323, 36443, 54436, 69403
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[189*2^# - 1] & ] (* Robert Price, Dec 29 2018 *)
PROG
(PARI) is(n)=ispseudoprime(189*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A206445 A047599 A332414 * A035538 A039881 A364652
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(48)-a(58) from the Wilfrid Keller link by Robert Price, Dec 29 2018
STATUS
approved