A050574 Numbers n such that 97*2^n-1 is prime.

1, 9, 45, 177, 585, 1409, 2617, 3465, 6981, 843205

Offset

1,2

Links

Table of n, a(n) for n=1..10.

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(97*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A036826 A022574 A321948 * A124647 A111640 A024209

Adjacent sequences: A050571 A050572 A050573 * A050575 A050576 A050577

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