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A032455
Numbers k such that 157*2^k+1 is prime.
0
8, 12, 14, 24, 32, 134, 252, 272, 404, 1460, 1776, 8510, 14280, 14396, 17736, 21284, 84056, 147036, 490772, 963590, 1920152, 2407958
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[157*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)
PROG
(PARI) is(n)=ispseudoprime(157*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A108979 A107071 A114414 * A342809 A279963 A050275
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(17)-a(21) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
a(22) from Jeppe Stig Nielsen, Apr 04 2020
STATUS
approved