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Numbers k such that 5^k + k^5 + 1 is prime.
4

%I #22 Sep 08 2022 08:46:03

%S 0,1,7,11,35,863,3503,5101

%N Numbers k such that 5^k + k^5 + 1 is prime.

%C a(9) > 2*10^5. - _Robert Price_, May 17 2014

%t Select[Range[0, 3000], PrimeQ[5^# + #^5 + 1] &]

%o (Magma) [n: n in [0..200] | IsPrime(5^n + n^5 + 1)]

%o (PARI) is(n)=ispseudoprime(5^n+n^5+1) \\ _Charles R Greathouse IV_, May 22 2017

%Y Cf. A215438.

%K nonn,more

%O 1,3

%A _Vincenzo Librandi_, Sep 03 2012

%E a(7)-a(8) from _Robert Price_, May 17 2014