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Numbers k such that k^3 + k - 1 is prime.
5

%I #15 Sep 02 2022 17:41:33

%S 3,4,7,10,15,16,18,21,25,27,33,36,39,43,46,51,52,55,63,73,78,81,87,93,

%T 94,96,100,103,105,109,112,115,117,120,124,127,129,135,139,145,150,

%U 151,165,166,171,178,189,192,198,199

%N Numbers k such that k^3 + k - 1 is prime.

%H Daniel Starodubtsev, <a href="/A236475/b236475.txt">Table of n, a(n) for n = 1..10000</a>

%e 46^3 + 46 - 1 = 97381 is prime. So 46 is a member of this sequence.

%t Select[Range[200],PrimeQ[#^3+#-1]&] (* _Harvey P. Dale_, Sep 02 2022 *)

%o (Python)

%o import sympy

%o from sympy import isprime

%o {print(n) for n in range(10**3) if isprime(n**3+n-1)}

%o (PARI)

%o s=[]; for(n=1, 500, if(isprime(n^3+n-1), s=concat(s, n))); s \\ _Colin Barker_, Jan 27 2014

%Y Cf. A049407, A126421.

%K nonn

%O 1,1

%A _Derek Orr_, Jan 26 2014