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A158615 Expansion of Sum_{n>0} n*n!*x^n/(1-n!*x^n). 1
1, 5, 19, 105, 601, 4445, 35281, 324897, 3266569, 36360065, 439084801, 5751188913, 80951270401, 1220673888257, 19615124183329, 334777645154817, 6046686277632001, 115243914079782593, 2311256907767808001 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) = Sum_{d|n} d*d!^(n/d).
LINKS
FORMULA
a(n) ~ n * n!. - Vaclav Kotesovec, Dec 19 2015
MAPLE
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
MATHEMATICA
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 *)
CROSSREFS
Sequence in context: A005165 A071828 A280067 * A321652 A088180 A206709
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Mar 22 2009
EXTENSIONS
More terms from R. J. Mathar, Mar 30 2009
STATUS
approved

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Last modified May 30 07:16 EDT 2023. Contains 363045 sequences. (Running on oeis4.)