A153183 Numbers k such that 3k-2 is prime.

3, 5, 7, 11, 13, 15, 21, 23, 25, 27, 33, 35, 37, 43, 47, 51, 53, 55, 61, 65, 67, 71, 75, 77, 81, 91, 93, 95, 103, 105, 111, 113, 117, 123, 125, 127, 133, 137, 141, 145, 147, 153, 155, 163, 167, 175, 181, 183, 191, 193, 201, 203, 205, 207, 211, 215, 221, 225, 231

Offset: 1

Author

Vincenzo Librandi, Dec 20 2008

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A153184 (complement)

Cf. A088878 (3p-2 is prime), A024892 (3*k+1 is prime).

Programs

Magma

[ n: n in [1..235] | IsPrime(3*n-2) ]; // Klaus Brockhaus, Dec 21 2008

Mathematica

Select[Range[1, 250], PrimeQ[(3*#)-2]&] (* Vincenzo Librandi, Sep 24 2012 *)

PARI

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

Formula

a(n) = A024892(n)+1. - Klaus Brockhaus, Dec 21 2008

Extensions

More terms from Klaus Brockhaus, Dec 21 2008