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A144425
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Nonprimes of the form (p(n)-2*(n-1))/7, where p(n)=n-th prime.
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0
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1, 33, 35, 39, 49, 77, 77, 105, 117, 119, 133, 145, 145, 155, 159, 185, 201, 205, 213, 213, 215, 225, 225, 235, 237, 243, 249, 255, 273, 295, 299, 301, 319, 319, 321, 327, 329, 341, 345, 345, 365, 375, 377, 381, 399, 405, 405, 413, 485, 485, 493, 493, 497
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..53.
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EXAMPLE
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If n=9, then (p(9)-2*(9-1))/7=(23-16)/7=1=a(1).
If n=75, then (p(75)-2*(75-1))/7=(379-148)/7=33=a(2).
If n=79, then (p(79)-2*(79-1))/7=(401-156)/7=35=a(3).
If n=86, then (p(86)-2*(86-1))/7=(443-170)/7=39=a(4).
If n=90, then (p(90)-2*(90-1))/7=(463-178)/7=49=a(5).
If n=143, then (p(143)-2*(143-1))/7=(823-284)/7=77=a(6), etc.
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MATHEMATICA
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Select[(Last[#]-2(First[#]-1))/7&/@Table[{n, Prime[n]}, {n, 800}], IntegerQ[#] && !PrimeQ[#]&] (* Harvey P. Dale, Sep 14 2011 *)
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CROSSREFS
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Cf. A000040, A141468.
Sequence in context: A344139 A140143 A041543 * A180329 A020260 A345500
Adjacent sequences: A144422 A144423 A144424 * A144426 A144427 A144428
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KEYWORD
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nonn
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AUTHOR
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Juri-Stepan Gerasimov, Oct 08 2008
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EXTENSIONS
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More terms from R. J. Mathar, Apr 13 2010
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STATUS
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approved
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