A109076 Numbers n such that 11^n + 2 is prime.

0, 1, 5, 9, 287, 8273, 121185, 303909

Offset

1,3

Comments

No further terms < 100000. - Ray Chandler, Jul 30 2011

a(8) > 2*10^5. - Robert Price, May 11 2014

Links

Table of n, a(n) for n=1..8.

Example

11^5 + 2 = 161053 is prime, hence 5 is a term.

Mathematica

Do[If[PrimeQ[11^n + 2], Print[n]], {n, 0, 5000}]

Prog

(PARI) is(n)=isprime(11^n+2) \\ Charles R Greathouse IV, Feb 17 2017

Crossrefs

Sequence in context: A002657 A046093 A097086 * A101683 A348132 A098135

Adjacent sequences: A109073 A109074 A109075 * A109077 A109078 A109079

Keyword

more,nonn

Author

Ryan Propper, Jun 17 2005

Extensions

8273 from Jason Earls, Feb 29 2008

Edited by N. J. A. Sloane, Mar 02 2008

a(7) from Robert Price, May 11 2014

a(8) from Paul Bourdelais, Aug 02 2023

Status

approved