A058911 Numbers k such that k^k + k + 1 is prime.

0, 1, 2, 3, 6, 9, 462

Offset

1,3

Comments

There is no further term up to 10000. - Farideh Firoozbakht, Nov 11 2006

If it exists, a(8) > 32100. - Dmitry Petukhov, Sep 14 2021

Links

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

Example

a(2) = 2 because 2^2 + 2 + 1 = 7.

Mathematica

Do[ If[ PrimeQ[ n^n + n + 1], Print[n]], {n, 1, 700} ]
Join[{0}, Select[Range[470], PrimeQ[#^#+#+1]&]] (* Harvey P. Dale, Dec 11 2022 *)

Prog

(PARI) f2(n, k) = for(x=1, n, y=x^x+x+k; if(ispseudoprime(y), print1(x", "))) \\ Cino Hilliard, Jan 07 2005
(PFGW) ABC2 $a^$a + $a + 1
a: from 0 to 1000 // Jinyuan Wang, Mar 01 2020

Crossrefs

Cf. A058912 (k^k + k - 1 is prime), A161471 (corresponding primes).

Sequence in context: A071714 A077753 A353122 * A249247 A276956 A276946

Adjacent sequences: A058908 A058909 A058910 * A058912 A058913 A058914

Keyword

nonn,hard,more

Author

Felice Russo, Jan 10 2001

Status

approved