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Search: id:A143545
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| 1, 4, 6, 4, 10, 6, 14, 8, 9, 10, 22, 12, 26, 14, 15, 16, 34, 18, 38, 20, 21, 22, 46, 24, 25, 26, 27, 28, 58, 30, 62, 32, 33, 34, 35, 36, 74, 38, 39, 40, 82, 42, 86, 44, 45, 46, 94, 48, 49, 50, 51, 52, 106, 54, 55, 56, 57, 58, 118, 60, 122, 62, 63, 64, 65, 66, 134, 68, 69, 70, 142
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OFFSET
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1,2
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FORMULA
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a(n) = n + A061397(n), where A061397 = (0, 2, 3, 0, 5, 0, 7,...). Equals row sums of triangle A143544. a(n) = n if n is a nonprime. If n is prime, a(n) = 2*n
a(n)=A066560(n), n>1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008]
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EXAMPLE
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a(3) = 6 = 2*3 since 3 is prime.
a(4) = 4 since 4 is a nonprime.
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CROSSREFS
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Cf. A143544, A061397.
Sequence in context: A088740 A088738 A114595 this_sequence A143521 A123969 A019188
Adjacent sequences: A143542 A143543 A143544 this_sequence A143546 A143547 A143548
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KEYWORD
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nonn
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AUTHOR
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Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 23 2008
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EXTENSIONS
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Extended beyond a(14) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008
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