A050575 Numbers n such that 99*2^n-1 is prime.

1, 4, 5, 7, 8, 11, 19, 25, 28, 35, 65, 79, 212, 271, 361, 461, 1237, 1297, 1577, 1747, 1901, 1943, 2741, 3203, 3425, 5069, 6368, 8372, 9761, 12260, 13472, 24032, 26227, 34028, 34492, 54244, 55660, 56056, 60965, 67283, 74576, 118711, 170867, 175921, 269809, 275113, 305803, 358891, 390373, 435301, 586088, 1106989

Offset

1,2

Links

Table of n, a(n) for n=1..52.

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(99*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A188322 A139201 A049649 * A081452 A047492 A240161

Adjacent sequences: A050572 A050573 A050574 * A050576 A050577 A050578

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