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A160892
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((2^b-1)/phi(n))*Sum_{d|n} Moebius(n/d)*d^(b-1) for b = 4.
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0
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15, 105, 195, 420, 465, 1365, 855, 1680, 1755, 3255, 1995, 5460, 2745, 5985, 6045, 6720, 4605, 12285, 5715, 13020, 11115, 13965, 8295, 21840, 11625, 19215, 15795, 23940, 13065, 42315, 14895, 26880, 25935, 32235, 26505, 49140, 21105, 40005
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OFFSET
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1,1
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REFERENCES
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J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161. See p. 134.
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LINKS
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Table of n, a(n) for n=1..38.
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FORMULA
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a(n) = 15*A160889(n). - R. J. Mathar, Feb 07 2011
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CROSSREFS
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Sequence in context: A219170 A223441 A102791 * A061550 A174385 A185129
Adjacent sequences: A160889 A160890 A160891 * A160893 A160894 A160895
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane, Nov 19 2009
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STATUS
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approved
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