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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 19 14:08 EDT 2021. Contains 345140 sequences. (Running on oeis4.)