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A158615
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Expansion of Sum_{n>0} n*n!*x^n/(1-n!*x^n).
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1
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1, 5, 19, 105, 601, 4445, 35281, 324897, 3266569, 36360065, 439084801, 5751188913, 80951270401, 1220673888257, 19615124183329, 334777645154817, 6046686277632001, 115243914079782593, 2311256907767808001
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OFFSET
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1,2
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COMMENTS
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a(n) = Sum_{d|n} d*d!^(n/d).
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LINKS
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FORMULA
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MAPLE
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nmax := 40: gf := add( taylor( n*n!*x^n/(1-n!*x^n), x=0, nmax+1), n=1..nmax ) : coeffs(convert(gf, polynom)) ; # R. J. Mathar, Mar 30 2009
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MATHEMATICA
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nmax=20; Rest[CoefficientList[Series[Sum[k*k!*x^k/(1-k!*x^k), {k, 1, nmax}], {x, 0, nmax}], x]] (* Vaclav Kotesovec, Dec 19 2015 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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