A236764 - OEIS

A236764

Numbers k such that k^3 +/- k +/- 1 are prime for all four possibilities.

%I #12 Mar 08 2020 11:35:04

%S 15,21,15375,25164,53361,95190,110685,115140,133701,139425,140430,

%T 140844,189336,217686,220650,266916,272469,289341,344880,364665,

%U 377805,382221,390270,415779,454905,539700,561186,567645,575799,584430,603651,722484

%N Numbers k such that k^3 +/- k +/- 1 are prime for all four possibilities.

%H Daniel Starodubtsev, <a href="/A236764/b236764.txt">Table of n, a(n) for n = 1..10000</a>

%e 110685^3+110685+1 (1356020665779811), 110685^3+110685-1 (1356020665779809), 110685^3-110685+1 (1356020665558441) and 110685^3-110685-1 (1356020665558439) are all prime. Thus 110685 is a member of this sequence.

%o (Python)

%o import sympy

%o from sympy import isprime

%o {print(n) for n in range(10**6) if isprime(n**3+n+1) and isprime(n**3-n+1) and isprime(n**3+n-1) and isprime(n**3-n-1)}

%o (PARI) for(n=1, 800000, if(isprime(n^3+n+1)&&isprime(n^3-n+1)&&isprime(n^3+n-1)&&isprime(n^3-n-1), print1(n, ","))) \\ _Colin Barker_, Jan 31 2014

%Y Intersection of A126421, A236477, A049407, and A236475.

%K nonn

%O 1,1

%A _Derek Orr_, Jan 30 2014