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A050888 Numbers n such that 259*2^n-1 is prime. 0
5, 7, 9, 27, 33, 37, 59, 179, 289, 389, 917, 1885, 2987, 3683, 4807, 8709, 10153, 11067, 11665, 18909, 22085, 32489, 36233, 143133, 202609, 278567, 316403, 347159, 423467, 425257, 427623 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..31.

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(259*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A029650 A049307 A050113 * A264349 A320114 A059485

Adjacent sequences:  A050885 A050886 A050887 * A050889 A050890 A050891

KEYWORD

hard,nonn

AUTHOR

N. J. A. Sloane, Dec 29 1999

EXTENSIONS

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

STATUS

approved

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Last modified November 15 18:10 EST 2018. Contains 317240 sequences. (Running on oeis4.)