login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A032409 Numbers k such that 119*2^k+1 is prime. 0
1, 3, 7, 13, 21, 23, 45, 63, 553, 1115, 2471, 2773, 7363, 25767, 26265, 32445, 41291, 55583, 113637, 376951, 787017, 858427, 915371, 1242207, 1759247 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..25.

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

MATHEMATICA

Select[Range[1000], PrimeQ[119*2^# + 1] & ] (* Robert Price, Dec 17 2018 *)

PROG

(PARI) is(n)=ispseudoprime(119*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A169633 A069194 A100531 * A073896 A299478 A299476

Adjacent sequences:  A032406 A032407 A032408 * A032410 A032411 A032412

KEYWORD

nonn,more

AUTHOR

James R. Buddenhagen

EXTENSIONS

Extended by Hugo Pfoertner, Jul 02 2003

a(20)-a(25) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 17 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 3 00:35 EDT 2020. Contains 333195 sequences. (Running on oeis4.)