A281483 Numbers k such that 32771*2^k + 1 is prime.

1, 13, 19, 29, 37, 45, 51, 61, 63, 65, 69, 117, 171, 181, 199, 201, 217, 221, 265, 337, 627, 631, 881, 1035, 1507, 1525, 1627, 1641, 2037, 3175, 4639, 6445, 21537, 29801, 30521, 30917, 37877, 49725, 50877, 57537, 61337, 118141, 125169, 200961, 204117, 283445, 395125, 829489

Offset: 1

Author

Pierre CAMI, Jan 22 2017

Keywords

• nonn

Comments

a(48) = 829489, 1438879 is such that 32771*2^1438879 + 1 is prime with 433151 digits, 829489 < a(49) <= 1438879.

Crossrefs

Cf. A002253.

Programs

Mathematica

Select[Range@ 3000, PrimeQ[32771*2^# + 1] &] (* Michael De Vlieger, Jan 23 2017 *)

PARI

list(limit)=my(i=1); while(iAnders Hellström, Feb 04 2017

PFGW

32771*2^$a+1
$a: from 1 to 1000001 step 2