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A002242
Numbers k such that 45*2^k - 1 is prime.
(Formerly M0502 N0181)
0
1, 2, 3, 4, 5, 6, 8, 9, 14, 15, 16, 22, 28, 29, 36, 37, 54, 59, 85, 93, 117, 119, 161, 189, 193, 256, 308, 322, 327, 411, 466, 577, 591, 902, 928, 946, 1162, 1428, 1708, 1724, 2063, 2922, 2951, 3111, 3402, 4024, 4485, 5859, 6124, 8981, 10628, 19283, 23522, 26591, 28914, 33954, 34743, 76367, 103546, 103912, 104452, 125132, 139883, 174102, 249065, 306394, 368553, 528245, 645542, 818648
OFFSET
1,2
REFERENCES
H. Riesel, Lucasian criteria for the primality of N=h.2^n-1, Math. Comp., 23 (1969), 869-875.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
PROG
(PARI) v=[ ]; for(n=1, 2000, if(isprime(45*2^n-1), v=concat(v, n), )); v
CROSSREFS
Sequence in context: A121644 A259623 A305734 * A317676 A039125 A203616
KEYWORD
hard,nonn
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
STATUS
approved