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A306159
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Inverse Weigh transform of 5^n.
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4
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5, 15, 40, 165, 624, 2620, 11160, 48915, 217000, 976872, 4438920, 20346320, 93900240, 435970980, 2034504992, 9536767665, 44878791360, 211927733500, 1003867701480, 4768372070592, 22706531339280, 108372083629260, 518301258916440, 2483526875798820
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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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Product_{k>=1} (1+x^k)^a(k) = 1/(1-5x).
a(n) = 1/n*(5^n + Sum_{d<n and d|n} (-1)^(n/d)*d*a(d)).
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EXAMPLE
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(1+x)^5*(1+x^2)^15*(1+x^3)^40*(1+x^4)^165* ... = 1 + 5*x + 25*x^2 + 125*x^3 + 625*x^4 + ... .
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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