A128829 Numbers k such that 6*k^2 + 17 is prime.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20, 21, 23, 25, 26, 27, 28, 30, 31, 33, 36, 37, 38, 41, 42, 44, 46, 48, 49, 50, 53, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 72, 73, 75, 76, 77, 79, 81, 82, 83, 89, 95, 96, 98, 100, 101, 103, 106, 107, 108, 110, 111, 113

Offset: 1

Author

J. M. Bergot, Apr 13 2007

Keywords

• nonn
• less
• easy

Examples

			6*8^2 + 17 = 401 is prime, hence 8 is a term.
		

Links

• Robert Price, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A151953.

Programs

Magma

[ n: n in [0..113] | IsPrime(6*n^2+17) ]; /* Klaus Brockhaus, Apr 16 2007 */

Maple

a:=proc(n) if isprime(6*n^2+17)=true then n else fi end: seq(a(n),n=0..150); # Emeric Deutsch, Apr 16 2007

Mathematica

f[a_]:=6*a^2+17; lst={};Do[If[PrimeQ[f[n]],AppendTo[lst,n]],{n,0,5!}];lst (* Vladimir Joseph Stephan Orlovsky, Jul 14 2009 *)
Select[Range[0,200],PrimeQ[6#^2+17]&] (* Harvey P. Dale, Jun 03 2014 *)

PARI

is(n)=isprime(6*n^2+17) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

Edited and extended by Klaus Brockhaus and Emeric Deutsch, Apr 16 2007