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A050551 Numbers n such that 51*2^n-1 is prime. 0
1, 9, 10, 19, 22, 57, 69, 97, 141, 169, 171, 195, 238, 735, 885, 1287, 1365, 2026, 2211, 2361, 2889, 3159, 3709, 5031, 19066, 33622, 43162, 188517, 194875, 217971, 286965, 331546, 468417, 657705, 832630 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

845494 is also in the sequence. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

LINKS

Table of n, a(n) for n=1..35.

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(51*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A231504 A298979 A299969 * A022099 A042113 A041166

Adjacent sequences:  A050548 A050549 A050550 * A050552 A050553 A050554

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

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Last modified December 9 22:27 EST 2019. Contains 329880 sequences. (Running on oeis4.)