A032363 Numbers k such that 27*2^k+1 is prime.

2, 4, 7, 16, 19, 20, 22, 26, 40, 44, 46, 47, 50, 56, 59, 64, 92, 175, 215, 275, 407, 455, 1076, 1090, 3080, 3322, 6419, 7639, 19360, 30500, 38770, 44164, 50696, 114760, 117784, 153847, 160874, 178739, 379880, 405514, 672007, 974752, 1164664, 1476347, 2218064

Offset

1,1

Links

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..47

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Ray Ballinger, Proth Search Page

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(27*2^n+1) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Cf. A050539 = 27*2^n-1 is prime.

Sequence in context: A364596 A280031 A135131 * A303749 A239390 A338647

Adjacent sequences: A032360 A032361 A032362 * A032364 A032365 A032366

Keyword

nonn,hard

Author

James R. Buddenhagen

Extensions

More terms from Hugo Pfoertner, Jun 20 2003

More terms from Hugo Pfoertner, Aug 17 2004

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

Status

approved