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

2, 4, 6, 32

Offset

1,1

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

Links

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

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 *)

Prog

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

Crossrefs

Cf. A100841 (corresponding primes).

Cf. A100837, A100839.

Sequence in context: A046847 A339759 A121069 * A056696 A045662 A195324

Adjacent sequences: A100835 A100836 A100837 * A100839 A100840 A100841

Keyword

hard,more,nonn

Author

Cino Hilliard, Jan 07 2005

Status

approved