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A179893
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a(n) = 3/2 * (prime(n)-1).
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2
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3, 6, 9, 15, 18, 24, 27, 33, 42, 45, 54, 60, 63, 69, 78, 87, 90, 99, 105, 108, 117, 123, 132, 144, 150, 153, 159, 162, 168, 189, 195, 204, 207, 222, 225, 234, 243, 249, 258, 267, 270, 285, 288, 294, 297, 315, 333, 339, 342, 348, 357, 360, 375, 384, 393, 402, 405
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OFFSET
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2,1
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LINKS
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G. C. Greubel, Table of n, a(n) for n = 2..1000
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FORMULA
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A179545 / prime(n).
a(n) = 3*A005097(n-1). - R. J. Mathar, Aug 15 2010
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EXAMPLE
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For n=4, the fourth prime is 7, so a(4) = (3/2) * (7 - 1) = 9. Note that since the sequence starts at n=2, prime(n) is odd, so a(n) is an integer. - Michael B. Porter, Jul 19 2016
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MATHEMATICA
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Table[(3/2)*(Prime[n] - 1), {n, 2, 100}] (* G. C. Greubel, Jun 17 2016 *)
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PROG
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(PARI) a(n)=prime(n)\2*3 \\ Charles R Greathouse IV, May 19 2011
(MAGMA) 3/2*(NthPrime(n)-1): n in [2..60]]; // Vincenzo Librandi, Jun 18 2016
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CROSSREFS
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Cf. A000040, A179545.
Sequence in context: A310175 A146562 A342594 * A274191 A133331 A276381
Adjacent sequences: A179890 A179891 A179892 * A179894 A179895 A179896
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KEYWORD
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easy,nonn
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AUTHOR
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Odimar Fabeny, Jul 30 2010, Aug 02 2010
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EXTENSIONS
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More terms from R. J. Mathar, Aug 15 2010
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STATUS
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approved
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