A050840 Numbers n such that 177*2^n-1 is prime.

1, 12, 13, 24, 25, 34, 36, 48, 61, 66, 196, 264, 376, 672, 732, 877, 1032, 1104, 1177, 1242, 2664, 7756, 35034, 37728, 57796, 96978, 98353, 277458, 282546, 418816, 582454, 653686, 663601, 665874, 668682, 769026

Offset

1,2

Links

Table of n, a(n) for n=1..36.

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(177*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A035123 A140212 A123132 * A108710 A108709 A138821

Adjacent sequences: A050837 A050838 A050839 * A050841 A050842 A050843

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