A156287 Numbers k such that 4*k-5 is a prime number.

2, 3, 4, 6, 7, 9, 12, 13, 16, 18, 19, 21, 22, 27, 28, 33, 34, 36, 39, 42, 43, 46, 49, 51, 54, 57, 58, 61, 64, 67, 69, 72, 78, 79, 84, 88, 91, 93, 96, 97, 106, 109, 111, 112, 117, 118, 121, 123, 124, 126, 127, 132, 138, 142, 144, 148, 151, 153, 156, 159, 162, 163, 166

Offset: 1

Author

Vincenzo Librandi, Feb 07 2009

Keywords

• nonn
• easy

Comments

Two more than the associated A095278, one more than the associated A005099. - R. J. Mathar, Jan 05 2011

Links

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

Crossrefs

Cf. A156288, A005099, A095278.

Programs

Magma

[n: n in [1..400] | IsPrime(4*n - 5)]; // Vincenzo Librandi, Feb 16 2013

Mathematica

Select[Range[600], PrimeQ[4 # - 5]&] (* Vincenzo Librandi, Feb 16 2013 *)