A038599 Numbers k such that k^3 - 2 is prime.

9, 15, 19, 27, 31, 37, 67, 91, 99, 109, 121, 129, 135, 145, 151, 165, 187, 189, 201, 207, 211, 217, 241, 259, 265, 267, 277, 279, 289, 319, 355, 357, 367, 369, 387, 391, 411, 417, 427, 435, 439, 445, 457, 459, 477, 489, 511, 525, 549, 555, 561, 615, 619, 621

Offset: 1

Author

Jeff Burch

Keywords

• nonn

Examples

			15^3 - 2 = 3373 is prime, so 15 is in the sequence.
		

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A038600, A028870, A028873.

Programs

Mathematica

a[n_]:=n^x-y;lst={};x=3;y=2;Do[If[PrimeQ[a[n]],AppendTo[lst,n]],{n,0,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Jan 03 2009 *)
Select[Range@ 640, PrimeQ[#^3 - 2] &] (* Michael De Vlieger, May 10 2016 *)

PARI

is(n)=isprime(n^3-2) \\ Charles R Greathouse IV, Feb 17 2017

Formula

a(n) = (A038600(n)+2)^(1/3). - Zak Seidov, May 10 2016

Extensions

Missed term, 207, and more terms added by Zak Seidov, Mar 14 2009