login
A053365
Numbers k such that 297*2^k + 1 is prime.
0
3, 6, 14, 15, 20, 27, 38, 123, 276, 327, 380, 411, 546, 819, 1155, 1274, 1800, 1875, 3135, 3411, 7514, 9446, 12615, 23400, 23564, 99344, 108258, 148988, 153818, 157623, 306596, 622800, 2660048
OFFSET
1,1
MATHEMATICA
Select[Range[5*10^3], PrimeQ[297*2^# + 1] &] (* G. C. Greubel, May 25 2018 *)
PROG
(PARI) is(n)=ispseudoprime(297*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
(Magma) [n: n in [1..3000] | IsPrime(297*2^n+1)]; // G. C. Greubel, May 25 2018
CROSSREFS
Sequence in context: A359669 A322183 A295292 * A101034 A342103 A084168
KEYWORD
hard,nonn,more
AUTHOR
N. J. A. Sloane, Dec 29 1999
EXTENSIONS
a(28)-a(32) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 22 2018
a(33) from Jeppe Stig Nielsen, Mar 12 2020
STATUS
approved