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Primes of form 5^k + k^5 - 1.
5

%I #7 Sep 08 2022 08:46:03

%S 5,367,2012173,1221074417,7450580596938177031

%N Primes of form 5^k + k^5 - 1.

%H Vincenzo Librandi, <a href="/A215437/b215437.txt">Table of n, a(n) for n = 1..7</a>

%t Select[Table[5^n + n^5 - 1, {n, 0, 500}], PrimeQ ]

%o (Magma) [ a: n in [0..250] | IsPrime(a) where a is 5^n + n^5 - 1 ]

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Sep 03 2012