A032362 Numbers k such that 25*2^k+1 is prime.

2, 4, 6, 10, 20, 22, 52, 64, 78, 184, 232, 268, 340, 448, 554, 664, 740, 748, 1280, 1328, 1640, 3314, 3904, 3938, 5152, 9522, 57488, 66872, 148060, 154254, 216092, 302194, 367294, 627710, 966414, 1211488, 1258562, 1298186, 2141884, 2583690, 2927222, 3733144

Offset

1,1

Links

Jeppe Stig Nielsen, 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(25*2^n+1) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Sequence in context: A317639 A164141 A034872 * A282251 A176716 A256056

Adjacent sequences: A032359 A032360 A032361 * A032363 A032364 A032365

Keyword

nonn,hard

Author

James R. Buddenhagen

Extensions

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

a(40)-a(42) from Jeppe Stig Nielsen, Sep 21 2019

Status

approved