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A100407
Numbers k such that k^k+2 is prime.
6
1, 3, 737, 1349
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
The next term, if it exists, is greater than 430000. - Ryan Propper, Dec 15 2023
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
KEYWORD
more,nonn,hard
AUTHOR
Farideh Firoozbakht, Nov 19 2004
STATUS
approved