%I
%S 1,3,9,13,27,225,505,1605,7417,9193,9235
%N Numbers k such that 5^k + k^5  1 is prime.
%C a(12) > 2*10^5.  _Robert Price_, May 24 2014
%t Select[Range[0, 3000], PrimeQ[5^# + #^5  1] &]
%o (MAGMA) [n: n in [0..300]  IsPrime(5^n + n^5  1)]
%o (PARI) is(n)=ispseudoprime(5^n+n^51) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A215437.
%K nonn,more
%O 1,2
%A _Vincenzo Librandi_, Sep 03 2012
%E a(9)a(11) from _Robert Price_, May 24 2014
