A155853 Numbers n such that 13*n + 3 is a prime.

0, 2, 8, 16, 20, 28, 32, 40, 46, 50, 58, 62, 68, 76, 82, 98, 100, 106, 110, 112, 116, 128, 130, 140, 146, 152, 160, 166, 170, 172, 188, 190, 196, 208, 218, 232, 250, 256, 266, 272, 278, 280, 296, 298, 302, 308, 316, 326, 338, 340, 358, 368, 370, 380, 382, 386

Offset: 1

Author

Vincenzo Librandi, Jan 29 2009

Keywords

• nonn
• easy

Comments

From Avik Roy (avik_3.1416(AT)yahoo.co.in), Feb 02 2009: (Start)

Only numbers of the form 6m+-2 can be included in this sequence.

All terms are evidently even and thus it can be concluded that 13n+3 can't be a prime if n itself is a prime greater than 2. (End)

Links

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

Crossrefs

Cf. A100202 (associated primes), A155854.

Programs

Magma

[n: n in [0..400] | IsPrime(13*n + 3)]; // Vincenzo Librandi, Oct 15 2012

Mathematica

f[n_]:=13*n+3; lst={};Do[p=f[n];If[PrimeQ[p],AppendTo[lst,n]],{n,0,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Jul 01 2009 *)
Select[Range[0, 800],PrimeQ[13 # + 3] &] (* Vincenzo Librandi, Oct 15 2012 *)

PARI

is(n)=isprime(13*n+3) \\ Charles R Greathouse IV, Aug 02 2018

Extensions

More terms from Vladimir Joseph Stephan Orlovsky, Jul 01 2009