%I #26 Sep 08 2022 08:46:03
%S 1,5,85,155,383,6223
%N Numbers k such that 13^k + k^13 - 1 is prime.
%C a(7) > 2*10^5 if it exists. - _Robert Price_, Jul 07 2014
%t Select[Range[0, 5000], PrimeQ[13^# + #^13 - 1] &]
%o (Magma) [n: n in [0..1000] | IsPrime(13^n+n^13-1)];
%o (PARI) is(n)=ispseudoprime(13^n+n^13-1) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A100357, A215434-A215437, A215439-A215445, A216375.
%K nonn,hard,more
%O 1,2
%A _Vincenzo Librandi_, Sep 07 2012
%E a(6) from _Robert Price_, May 24 2014