A228358 Numbers n such that 3*n - 4 is not prime.

1, 4, 6, 8, 10, 12, 13, 14, 16, 18, 20, 22, 23, 24, 26, 27, 28, 30, 32, 33, 34, 36, 38, 40, 41, 42, 43, 44, 46, 48, 49, 50, 52, 53, 54, 55, 56, 58, 60, 62, 63, 64, 66, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 80, 82, 83, 84, 86, 88, 90, 92, 93, 94, 96, 97, 98, 100, 101

Offset: 1

Author

Vincenzo Librandi, Aug 21 2013

Keywords

• nonn
• easy

Comments

After 1, all terms are given by A153170 +2. [Bruno Berselli, Aug 21 2013]

Examples

			8 is in the sequence since 3*8 - 4 = 20 is not prime.
		

Links

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

Crossrefs

Cf. A153170, A228121.

Programs

Magma

[n: n in [1..120] | not IsPrime(3*n -4)];

Mathematica

Select[Range[230], ! PrimeQ[3 # - 4]&]