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A050851 Numbers k such that 199*2^k-1 is prime. 0
1, 5, 7, 15, 19, 23, 25, 27, 43, 65, 99, 125, 141, 165, 201, 211, 331, 369, 389, 445, 461, 463, 467, 513, 583, 835, 1071, 1085, 1107, 1187, 1197, 1491, 1513, 2505, 3859, 3941, 5989, 9693, 13125, 17009, 19459, 33147, 46433, 51091, 72813, 105169, 118531, 153127 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
MATHEMATICA
Select[Range[1000], PrimeQ[199*2^# - 1] & ] (* Robert Price, Dec 29 2018 *)
PROG
(PARI) is(n)=ispseudoprime(199*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A321130 A320381 A309292 * A058918 A079360 A314365
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) from the Wilfrid Keller link by Robert Price, Dec 29 2018
STATUS
approved

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Last modified July 22 13:14 EDT 2024. Contains 374499 sequences. (Running on oeis4.)