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A215443
Numbers k such that 5^k + k^5 - 1 is prime.
1
1, 3, 9, 13, 27, 225, 505, 1605, 7417, 9193, 9235
OFFSET
1,2
COMMENTS
a(12) > 2*10^5. - Robert Price, May 24 2014
MATHEMATICA
Select[Range[0, 3000], PrimeQ[5^# + #^5 - 1] &]
PROG
(Magma) [n: n in [0..300] | IsPrime(5^n + n^5 - 1)]
(PARI) is(n)=ispseudoprime(5^n+n^5-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A215437.
Sequence in context: A018407 A304350 A305913 * A304664 A068885 A305644
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Sep 03 2012
EXTENSIONS
a(9)-a(11) from Robert Price, May 24 2014
STATUS
approved