A153051 Numbers n>=9 such that 2*n-17 is not a prime.

9, 13, 16, 19, 21, 22, 25, 26, 28, 31, 33, 34, 36, 37, 40, 41, 43, 46, 47, 49, 51, 52, 54, 55, 56, 58, 61, 64, 66, 67, 68, 69, 70, 71, 73, 75, 76, 79, 80, 81, 82, 85, 86, 88, 89, 91, 93, 94, 96, 97, 100, 101, 102, 103, 106, 109, 110, 111, 112, 113, 115, 116, 117, 118, 119

Offset: 1

Author

Vincenzo Librandi, Dec 17 2008

Keywords

• nonn
• easy

Comments

Adding 1 to each entry yields A153041. [From R. J. Mathar, Dec 19 2008]

The terms after a(1) are the values of 2*h*k + k + h + 9, where h and k are positive integers.- Vincenzo Librandi, Jan 19 2013

Links

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

Crossrefs

Cf. A098605, A163674.

Programs

Magma

[n: n in [9..150] | not IsPrime(2*n - 17)]; // Vincenzo Librandi, Jan 19 2013

Mathematica

Select[Range[9, 200], !PrimeQ[2 # - 17] &] (* Vincenzo Librandi, Jan 19 2013 *)

Extensions

57 removed by R. J. Mathar, Dec 19 2008