login
A050889
Numbers n such that 261*2^n-1 is prime.
0
1, 3, 6, 9, 21, 34, 43, 49, 114, 115, 178, 322, 411, 438, 454, 589, 598, 754, 801, 1173, 1546, 1699, 2155, 2994, 4038, 5439, 6442, 10699, 12274, 13314, 13911, 19309, 28675, 29658, 31173, 33606, 65763, 90861, 116706, 185823, 618918, 660709, 802123
OFFSET
1,2
PROG
(PARI) is(n)=ispseudoprime(261*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A116614 A089001 A215666 * A327140 A329863 A026095
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