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A100837
Numbers k such that k^k + 4 is prime.
8
0, 1, 3, 7, 43, 2569
OFFSET
1,3
COMMENTS
From a post in [primeNumbers].
Here we interpret 0^0 as 1.
Next term exceeds 15000. - Sean A. Irvine, Sep 09 2009
Next term exceeds 25000. - Michael S. Branicky, Jun 28 2024
MATHEMATICA
For[n = 1, n < 1000, n++, If[ PrimeQ[n^n + 4], Print[n]]] (* Stefan Steinerberger, Apr 02 2006 *)
PROG
(PARI) f1(n, a) = for(x=0, n, y=x^x+a; if(ispseudoprime(y), print1(y", ")))
CROSSREFS
Cf. A100840 (corresponding primes).
Sequence in context: A156893 A050639 A280717 * A253576 A354428 A328690
KEYWORD
hard,more,nonn
AUTHOR
Cino Hilliard, Jan 07 2005
EXTENSIONS
a(6) from Sean A. Irvine, Sep 09 2009
STATUS
approved