A050857 Numbers n such that 211*2^n-1 is prime.

1, 13, 23, 37, 43, 67, 83, 151, 661, 811, 3937, 5027, 5365, 9307, 11971, 60295, 89071, 89303, 262877

Offset

1,2

Links

Table of n, a(n) for n=1..19.

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

Kosmaj, Riesel list k<300.

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

Prog

(PARI) is(n)=ispseudoprime(211*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A108794 A272721 A089777 * A089714 A070219 A046119

Adjacent sequences: A050854 A050855 A050856 * A050858 A050859 A050860

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