| 1, 1, 1, 5, 1, 7, 1, 13, 10, 11, 1, 23, 1, 15, 16, 29, 1, 34, 1, 35, 22, 23, 1, 55, 26, 27, 37, 47, 1, 62, 1, 61, 34, 35, 36, 86, 1, 39, 40, 83, 1, 84, 1, 71, 70, 47, 1, 119, 50, 86, 52, 83, 1, 115, 56, 111, 58, 59, 1, 158, 1, 63, 94, 125, 66, 128, 1, 107, 70, 130, 1, 190, 1, 75
(list; graph; listen)
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OFFSET
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1,4
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..1000
Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.
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FORMULA
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Equals A051731 * A037282 - Gary W. Adamson (qntmpkt(AT)yahoo.com), Nov 06 2007
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MATHEMATICA
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Array[ Plus @@ (Select[ Divisors[ # ], (!PrimeQ[ # ])& ])&, 75 ]
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PROGRAM
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(PARI) a(n)=if(n<1, 0, sumdiv(n, d, !isprime(d)*d)) /* Michael Somos Jun 08 2005 */
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CROSSREFS
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Cf. A051731, A037282.
Sequence in context: A051712 A086892 A089027 this_sequence A102778 A135544 A051724
Adjacent sequences: A023887 A023888 A023889 this_sequence A023891 A023892 A023893
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KEYWORD
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nonn,nice,easy
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AUTHOR
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Olivier Gerard (ogerard(AT)ext.jussieu.fr)
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