A100407 Numbers k such that k^k+2 is prime.

1, 3, 737, 1349

Offset: 1

Author

Farideh Firoozbakht, Nov 19 2004

Keywords

• more
• nonn
• hard

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

Examples

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

Crossrefs

Cf. A100408.

Programs

Mathematica

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

PARI

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