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 A032359 Numbers k such that 19*2^k+1 is prime. 2
 6, 10, 46, 366, 1246, 2038, 4386, 4438, 6838, 7498, 7998, 9450, 11890, 17034, 23290, 73338, 149146, 323638, 853546, 2206266, 6833086 (list; graph; refs; listen; history; text; internal format)
 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

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Last modified May 26 13:25 EDT 2024. Contains 372826 sequences. (Running on oeis4.)