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A050618
Numbers k such that 153*2^k-1 is prime.
0
3, 4, 6, 7, 10, 11, 12, 19, 20, 22, 23, 39, 66, 106, 120, 124, 151, 312, 411, 447, 474, 507, 574, 671, 787, 826, 979, 1690, 1954, 2047, 3003, 4323, 4426, 5903, 6267, 6846, 14550, 17470, 21520, 31711, 36724, 45291, 45654, 51778, 55420, 63439, 68451, 78423, 109696, 125128, 130710, 169836, 192900, 195028, 383083, 545716
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[153*2^# - 1] & ] (* Robert Price, Dec 23 2018 *)
PROG
(PARI) is(n)=ispseudoprime(153*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A135215 A092494 A274429 * A093579 A347752 A060832
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(49)-a(56) from the Wilfrid Keller link by Robert Price, Dec 23 2018
STATUS
approved