A050564 - OEIS

A050564

Numbers n such that 77*2^n-1 is prime.

2, 4, 14, 26, 58, 60, 64, 100, 122, 212, 566, 638, 1214, 2080, 4852, 5356, 5720, 7044, 8320, 8556, 10684, 14584, 39016, 47972, 72008, 217956, 223512, 387680, 441528, 607920, 855770

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OFFSET

1,1

COMMENTS

1467554 is also a member. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

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(77*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A102930 A357996 A135113 * A047830 A036051 A115626

Adjacent sequences: A050561 A050562 A050563 * A050565 A050566 A050567

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