A160681 Primes of form 10 * 2^(2^n) + 19.

59, 179, 2579, 655379, 42949672979, 184467440737095516179, 3402823669209384634633746074317682114579

Offset

1,1

Comments

Primes of the form 10*A000215(n) + 9. - Arkadiusz Wesolowski, Mar 04 2011

a(n) is composite for n = 0 and all 8 <= n <= 26. - Arkadiusz Wesolowski, Oct 21 2013

Links

Table of n, a(n) for n=1..7.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 9

Mathematica

Select[Table[10*2^2^n + 19, {n, 0, 7}], PrimeQ] (* Arkadiusz Wesolowski, Mar 04 2011 *)

Prog

(Magma) [10*2^2^n+19 : n in [0..7] | IsPrime(10*2^2^n+19)]; // Arkadiusz Wesolowski, Mar 04 2011
(PARI) for(n=0, 7, if(isprime(x=(10*2^2^n+19)), print1(x, ", "))); \\ Arkadiusz Wesolowski, Mar 04 2011

Crossrefs

Cf. A030433, A000215.

Sequence in context: A142799 A250025 A140626 * A142857 A142064 A114353

Adjacent sequences: A160678 A160679 A160680 * A160682 A160683 A160684

Keyword

nonn,hard

Author

Arkadiusz Wesolowski, May 23 2009

Status

approved