A153219 Numbers n such that 6*n + 7 is not prime.

3, 7, 8, 13, 14, 18, 19, 21, 23, 27, 28, 30, 33, 35, 38, 40, 41, 42, 43, 47, 48, 49, 52, 53, 56, 58, 59, 63, 64, 66, 68, 70, 73, 74, 77, 78, 79, 81, 83, 84, 85, 87, 88, 91, 92, 93

Offset

1,1

Comments

One less than the associated entry in A046954. - R. J. Mathar, Jan 05 2011

Links

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

Example

Distribution of the terms in the following triangular array:
*;
*,3;
*,*,7;
*,*,*,*;
*,8,*,*,19;
*,*,14,*,*,27;
*,*, *,*,*, *,*;
*,13,*,*,30,*,*,47;
*,*,21,*,*,40,*,*,59;
*,*,*, *,*, *,*,*, *,*;
*,18,*,*,41,*,*,64,*,*,87;
*,*,28,*,*,53,*,*,78,*,*,103; etc.
where * marks the non-integer values of (2*h*K + k + h - 3)/3 with h >= k >= 1. - Vincenzo Librandi, Jan 15 2013

Mathematica

Select[Range[0, 200], !PrimeQ[6 # + 7] &] (* Vincenzo Librandi, Jan 12 2013 *)

Prog

(Magma) [n: n in [0..110] | not IsPrime(6*n+7)]; // Vincenzo Librandi, Jan 12 2013

Crossrefs

Cf. A153218.

Sequence in context: A031425 A063657 A108575 * A264720 A215034 A050014

Adjacent sequences: A153216 A153217 A153218 * A153220 A153221 A153222

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 21 2008

Status

approved