A050865 Numbers n such that 227*2^n-1 is prime.

2, 4, 8, 12, 14, 26, 32, 80, 124, 230, 284, 562, 866, 1830, 2630, 3122, 3428, 6278, 9900, 19888, 20092, 22706, 29088, 31412, 44402, 47914, 53120, 102330, 135164, 299306, 345918

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(227*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A160162 A328838 A064711 * A354109 A354919 A288514

Adjacent sequences: A050862 A050863 A050864 * A050866 A050867 A050868

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