A175168 Numbers k such that 2^(k-1) mod k is a prime number.

6, 10, 14, 22, 26, 27, 30, 34, 38, 45, 46, 58, 62, 74, 82, 86, 94, 106, 118, 122, 134, 142, 146, 153, 155, 158, 166, 170, 178, 182, 189, 194, 202, 206, 214, 215, 218, 226, 231, 254, 262, 274, 278, 287, 297, 298, 302, 314, 323

Offset

1,1

Comments

Numbers k such that A062173(k) is prime.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[323], PrimeQ[Mod[2^(#-1), #]] &]
Select[Range[350], PrimeQ[PowerMod[2, #-1, #]]&] (* Harvey P. Dale, Jun 07 2016 *)

Crossrefs

Cf. A000040, A062173.

Sequence in context: A015812 A358776 A315232 * A315233 A360014 A315234

Adjacent sequences: A175165 A175166 A175167 * A175169 A175170 A175171

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 02 2010

Status

approved