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A032424 Numbers k such that 149*2^k+1 is prime. 0
3, 7, 9, 15, 17, 27, 33, 35, 57, 125, 127, 137, 191, 513, 819, 827, 921, 931, 1047, 1147, 1599, 1815, 2499, 2995, 8151, 11403, 22783, 29841, 30201, 85935, 142281, 149831, 184457, 221595, 256099, 283881, 333933, 483045, 658917, 714199, 812719, 1295061, 1561951 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The subsequence of prime values starts 3, 7, 17, 127, 137, 191, 827, 22783, 714199, ... - Muniru A Asiru, Apr 29 2019

LINKS

Table of n, a(n) for n=1..43.

Ray Ballinger, Proth Search Page

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Y. Gallot, Proth.exe: Windows Program for Finding Large Primes

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

MAPLE

select(k->isprime(149*2^k+1), [$0..1000])[]; # Muniru A Asiru, Dec 18 2018

MATHEMATICA

Select[Range[1000], PrimeQ[149*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

PROG

(PARI) is(n)=ispseudoprime(149*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A178207 A210532 A110872 * A280861 A287264 A187108

Adjacent sequences:  A032421 A032422 A032423 * A032425 A032426 A032427

KEYWORD

nonn,more

AUTHOR

James R. Buddenhagen

EXTENSIONS

Extended by Hugo Pfoertner, Jul 02 2003

a(33)-a(43) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

STATUS

approved

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Last modified December 7 20:40 EST 2021. Contains 349589 sequences. (Running on oeis4.)