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A153219
Numbers n such that 6*n + 7 is not prime.
3
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
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
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 21 2008
STATUS
approved