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A092148
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Expansion of e.g.f. 1/(exp(x)-x*exp(2*x)).
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4
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1, 0, 3, 11, 85, 739, 7831, 96641, 1363209, 21632759, 381433771, 7398080029, 156533563693, 3588046200179, 88571349871551, 2342565398442569, 66087436823953681, 1980956920420309231, 62871632567144951635, 2106277265332074827573, 74276723394195659799861
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = n! * Sum_{k=0..n} (n-k-1)^k/k!. [Corrected by Georg Fischer, Jun 22 2022]
a(n) ~ n! / ((LambertW(1) + 1) * LambertW(1)^(n-1)). - Vaclav Kotesovec, Jun 22 2022
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MATHEMATICA
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With[{nn=20}, CoefficientList[Series[1/(Exp[x]-x Exp[2x]), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Sep 19 2020 *)
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PROG
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(PARI) a(n)=(n)!*sum(k=0, n, (n-k-1)^k/k!))
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CROSSREFS
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KEYWORD
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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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