A024909 Numbers k such that 9*k - 4 is prime.

1, 3, 5, 7, 13, 15, 17, 19, 27, 29, 33, 35, 39, 43, 45, 47, 55, 57, 63, 67, 69, 73, 83, 85, 89, 99, 105, 109, 113, 115, 117, 123, 133, 137, 143, 145, 147, 153, 157, 159, 165, 167, 173, 175, 179, 189, 193, 199, 203, 209, 213, 215, 217, 223, 227, 235, 237, 249, 253, 257, 265, 267

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A061240 (associated primes).

Programs

Magma

[n: n in [1..300] | IsPrime(9*n-4)]; // Vincenzo Librandi, Nov 19 2010

Mathematica

Select[Range[400], PrimeQ[9# - 4] &] (* Vincenzo Librandi, Sep 26 2012 *)

PARI

is(n)=isprime(9*n-4) \\ Charles R Greathouse IV, Jun 06 2017