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!)
A032400 Numbers k such that 101*2^k+1 is prime. 0
3, 9, 17, 21, 27, 39, 45, 47, 71, 95, 117, 123, 143, 173, 387, 389, 513, 633, 827, 971, 1103, 3767, 3831, 7695, 8871, 9809, 10011, 17513, 17873, 22841, 25401, 84369, 95315, 168983, 382407, 488039, 534891, 687897, 715503, 1142981, 1988279, 2009735, 2212769 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

PROG

(PARI) is(n)=ispseudoprime(101*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A050795 A050797 A103967 * A329422 A004621 A014209

Adjacent sequences:  A032397 A032398 A032399 * A032401 A032402 A032403

KEYWORD

nonn

AUTHOR

James R. Buddenhagen

EXTENSIONS

More terms from Hugo Pfoertner, Jun 20 2003

More terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), Joerg Arndt, Apr 07 2013

a(41)-a(42) from http://www.prothsearch.com/riesel1.html by Robert Price, Dec 14 2018

a(43) from Jeppe Stig Nielsen, Apr 19 2020

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 July 25 03:53 EDT 2021. Contains 346283 sequences. (Running on oeis4.)