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A050591 Numbers n such that 131*2^n-1 is prime. 0
2, 14, 34, 38, 42, 78, 90, 178, 778, 974, 1878, 3718, 4050, 5466, 6478, 35662, 40046, 56346, 98626, 131026, 138658 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also in the sequence: 603738 - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

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(131*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A322074 A083015 A282036 * A073535 A225292 A060626

Adjacent sequences:  A050588 A050589 A050590 * A050592 A050593 A050594

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 September 24 07:01 EDT 2020. Contains 337317 sequences. (Running on oeis4.)