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A038069
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Product_{k>=1} ((1 + x^k)^a(k)) = 1 + 4x.
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7
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4, -6, 20, -66, 204, -670, 2340, -8226, 29120, -104754, 381300, -1398410, 5162220, -19172790, 71582716, -268439586, 1010580540, -3817733920, 14467258260, -54975633702, 209430785460, -799644629550, 3059510616420
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OFFSET
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1,1
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LINKS
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FORMULA
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Dirichlet convolution of A038065 with characteristic function of powers of 2.
a(n) = (1/n)*(-(-4)^n + Sum_{d<n and d|n} (-1)^(n/d)*d*a(d)). - Seiichi Manyama, Jun 23 2018
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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