A032359 Numbers k such that 19*2^k+1 is prime.

6, 10, 46, 366, 1246, 2038, 4386, 4438, 6838, 7498, 7998, 9450, 11890, 17034, 23290, 73338, 149146, 323638, 853546, 2206266, 6833086

Offset

1,1

Links

Table of n, a(n) for n=1..21.

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(19*2^n+1) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Sequence in context: A153328 A068588 A083333 * A346501 A115917 A275004

Adjacent sequences: A032356 A032357 A032358 * A032360 A032361 A032362

Keyword

nonn,hard

Author

James R. Buddenhagen

Extensions

Added more terms (from http://www.prothsearch.com/riesel1.html), Joerg Arndt, Apr 07 2013

a(21) from Jeppe Stig Nielsen, Oct 30 2020

Status

approved