

A100407


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


6




OFFSET

1,2


COMMENTS

All terms are odd. Next term is greater than 3500. 1349^1349+2 is a probable prime with length 4223.
The next term, if it exists, is greater than 50000.  Hugo Pfoertner, Jun 28 2019


LINKS

Table of n, a(n) for n=1..4.


EXAMPLE

737 is in the sequence because 737^737+2 is prime.


MATHEMATICA

Do[If[PrimeQ[n^n+2], Print[n]], {n, 3500}]


PROG

(PARI) is(n)=ispseudoprime(n^n+2) \\ Charles R Greathouse IV, May 22 2017


CROSSREFS

Cf. A100408.
Sequence in context: A013826 A255012 A133014 * A332173 A119264 A307926
Adjacent sequences: A100404 A100405 A100406 * A100408 A100409 A100410


KEYWORD

more,nonn,hard


AUTHOR

Farideh Firoozbakht, Nov 19 2004


STATUS

approved



