A002240 Numbers k such that 33*2^k - 1 is prime. (Formerly M0752 N0284)

2, 3, 6, 8, 10, 22, 35, 42, 43, 46, 56, 91, 102, 106, 142, 190, 208, 266, 330, 360, 382, 462, 503, 815, 1038, 1651, 1855, 1858, 1992, 2232, 4462, 4726, 5475, 6702, 9710, 10931, 11503, 20552, 22291, 26575, 35931, 39271, 51326, 57695, 63115, 67182, 109848, 128635, 136971, 173110, 174182, 373446, 585400, 598248, 674050, 773030

Offset

1,1

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).

Links

Table of n, a(n) for n=1..56.

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Kosmaj, Riesel list k<300.

Prog

(PARI) is(n)=ispseudoprime(33*2^n-1) \\ Charles R Greathouse IV, May 22 2017

Crossrefs

Sequence in context: A098162 A076627 A020489 * A099798 A230108 A097383

Adjacent sequences: A002237 A002238 A002239 * A002241 A002242 A002243

Keyword

hard,nonn

Author

N. J. A. Sloane

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Status

approved