A050839 Numbers n such that 175*2^n-1 is prime.

1, 3, 9, 21, 23, 41, 47, 57, 69, 83, 193, 249, 291, 421, 433, 997, 1269, 1619, 1893, 2457, 3527, 9579, 14699, 15677, 16479, 21293, 30729, 33609, 47437, 143691, 244073, 244393, 282719, 309593, 387513, 529417

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(175*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A365919 A109612 A032668 * A032640 A245202 A127174

Adjacent sequences: A050836 A050837 A050838 * A050840 A050841 A050842

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