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A054606
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a(n) = Sum_{d|7} phi(d)*n^(7/d).
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2
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0, 7, 140, 2205, 16408, 78155, 279972, 823585, 2097200, 4783023, 10000060, 19487237, 35831880, 62748595, 105413588, 170859465, 268435552, 410338775, 612220140, 893871853, 1280000120, 1801088667, 2494358020, 3404825585
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = n^7 + 6n.
G.f.: 7*x*(x^6+12*x^5+183*x^4+328*x^3+183*x^2+12*x+1) / (x-1)^8. [Colin Barker, Dec 21 2012]
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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