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A050562 Numbers n such that 73*2^n-1 is prime. 0
7, 11, 19, 71, 79, 131, 1167, 1191, 6771, 12627, 17947, 20079, 26347, 40327, 41231, 69379, 109587, 193559, 212451, 499391, 783831 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..21.

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(73*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A023267 A319224 A282037 * A321806 A057190 A106674

Adjacent sequences:  A050559 A050560 A050561 * A050563 A050564 A050565

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 August 17 17:25 EDT 2019. Contains 326059 sequences. (Running on oeis4.)