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A153245
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Numbers n>1 such that 6*n-7 is not prime.
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4
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7, 12, 14, 17, 21, 22, 25, 27, 28, 32, 35, 36, 37, 38, 42, 47, 49, 51, 52, 55, 56, 57, 58, 62, 63, 64, 67, 69, 70, 72, 74, 77, 80, 82, 84, 87, 89, 90, 91, 92, 93, 97, 98, 102, 103, 105, 106, 107, 112, 113, 116, 117, 119, 120, 122, 123, 124, 126, 127, 129, 131, 132, 133
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OFFSET
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1,1
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COMMENTS
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One more than the associated value in A046953. - R. J. Mathar, Jan 05 2011
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 1..1000
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EXAMPLE
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Distribution of the terms in the following triangular array:
*;
*,*;
*,7,*;
*,*,*,*;
*,*,14,*,*;
*,12,*,*,25,*;
*, *,*,*,*, *,*;
*,*,21,*,*,38,*,*;
*,17,*,*,36,*,*,55,*;
*,*, *,*,*, *,*,*, *,*;
*,*,28,*,*,51,*,*,74,*,*;
*,22,*,*,47,*,*,72,*,*,97,*; etc.
where * marks the non-integer values of (2*h*k + k + h + 4)/3 with h >= k >= 1. - Vincenzo Librandi, Jan 17 2013
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MATHEMATICA
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Select[Range[2, 200], !PrimeQ[6 # - 7] &] (* Vincenzo Librandi, Jan 12 2013 *)
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PROG
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(MAGMA) [n: n in [2..150] | not IsPrime(6*n - 7)]; // Vincenzo Librandi, Jan 12 2013
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CROSSREFS
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Cf. A153134, A153135.
Sequence in context: A078835 A173417 A031021 * A062730 A073255 A162194
Adjacent sequences: A153242 A153243 A153244 * A153246 A153247 A153248
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KEYWORD
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nonn,easy
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AUTHOR
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Vincenzo Librandi, Dec 21 2008
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EXTENSIONS
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More terms from Vladimir Joseph Stephan Orlovsky, Dec 23 2008
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STATUS
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approved
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