A100838 Numbers k such that k^k + 7 is prime.

2, 4, 6, 32

Offset: 1

Author

Cino Hilliard, Jan 07 2005

Keywords

• hard
• more
• nonn

Comments

Here we interpret 0^0 as 1.

a(5) > 3000. - Daniel Starodubtsev, Aug 07 2019

a(5) > 17000. - Michael S. Branicky, Jun 29 2024

Crossrefs

Cf. A100841 (corresponding primes).

Cf. A100837, A100839.

Programs

Mathematica

lst={};Do[p=n^n+7;If[PrimeQ[p],AppendTo[lst,n]],{n,2*5!}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 01 2009 *)
Select[Range[35],PrimeQ[#^#+7]&] (* Harvey P. Dale, Oct 27 2018 *)

PARI

f1(n,a) = for(x=0,n,y=x^x+a;if(ispseudoprime(y),print1(y",")))