A050879 - OEIS

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A050879

Numbers n such that 241*2^n-1 is prime.

0

11, 17, 19, 39, 69, 321, 653, 1109, 3819, 5729, 9659, 9911, 13217, 16707, 22307, 65107, 75419, 97587, 99667, 336197, 407709, 497679

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..22.

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(241*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A230654 A226686 A217055 * A245622 A050669 A362083

Adjacent sequences: A050876 A050877 A050878 * A050880 A050881 A050882

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