A124154 Numbers n such that 1 + n + n^3 + n^5 is prime.

2, 4, 8, 20, 22, 32, 36, 50, 54, 62, 64, 72, 78, 84, 86, 90, 92, 94, 96, 98, 112, 124, 134, 144, 146, 216, 224, 238, 240, 246, 250, 256, 262, 276, 294, 296, 298, 300, 314, 334, 370, 378, 382, 392, 400, 402, 406, 420, 430, 450, 472, 480, 482, 494, 510, 512, 526

Offset: 1

Author

Artur Jasinski, Dec 13 2006

Keywords

• nonn
• easy

Comments

All numbers n have to be even, because sum of 3 odd + 1 is even and can't be prime >3.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A049407, similar sequences listed in A244376.

Programs

Magma

[n: n in [0..600] | IsPrime(s) where s is 1+&+[n^i: i in [1..5 by 2]]]; // Vincenzo Librandi, Jun 27 2014

Mathematica

Do[If[PrimeQ[1 + n + n^3 + n^5], Print[n]], {n, 1, 300}]
Select[Range[1000], PrimeQ[Total[#^Range[1, 5, 2]] + 1] &] (* Vincenzo Librandi, Jun 27 2014 *)

PARI

forstep(n=2,1000,2,if(isprime(1 + n + n^3 + n^5), print1(n","))) \\ Franklin T. Adams-Watters, Apr 09 2009

Extensions

More terms from Franklin T. Adams-Watters, Apr 09 2009