|
%I #13 Jul 13 2023 15:26:38
%S 1,2,4,5,7,17,22,47,155,167,203,277,469,629,890,1427,4507,5705,6095,
%T 9808,10108,12797,16184,31535,33575
%N Numbers k such that k^3 + 3*k + 3^k is prime.
%t Select[Range[10000], PrimeQ[#^3 + 3*# + 3^#]&]
%o (PARI) is(n)=ispseudoprime(n^3+3*n+3^n) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A220509.
%K nonn,more
%O 1,2
%A _Vincenzo Librandi_, Jan 07 2013
%E a(21)-a(25) from _Michael S. Branicky_, Jul 13 2023
|
