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A100838
Numbers k such that k^k + 7 is prime.
8
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
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).
Sequence in context: A046847 A339759 A121069 * A056696 A045662 A195324
KEYWORD
hard,more,nonn
AUTHOR
Cino Hilliard, Jan 07 2005
STATUS
approved