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A132958
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a(n) = n!*Sum_{d|n} (-1)^(d+1)/d!.
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6
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1, 1, 7, 11, 121, 479, 5041, 18479, 423361, 1844639, 39916801, 298710719, 6227020801, 43606442879, 1536517382401, 9589093113599, 355687428096001, 4259374594675199, 121645100408832001, 1135353600039859199
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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FORMULA
| E.g.f.: Sum_{k>0} (-x)^k/(k!*(x^k-1)) or Sum_{k>0}(1-exp(-x^k)).
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MATHEMATICA
| f[n_] := Block[{d = Divisors@n}, Plus @@ (n!*(-1)^(d + 1)/d!)]; Array[f, 19] (* or *) - Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 13 2007
Rest[ Range[0, 20]! CoefficientList[ Series[ Sum[(-x)^k/(k!*(x^k - 1)), {k, 25}], {x, 0, 20}], x]] (* or *) - Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 13 2007
Rest[ Range[0, 20]! CoefficientList[ Series[ Sum[1 - Exp[ -x^k], {k, 25}], {x, 0, 20}], x]] - Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 13 2007
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CROSSREFS
| Cf. A057625, A132959, A132960, A132961, A132962, A132963.
Sequence in context: A123763 A018680 A107187 * A057737 A130704 A038543
Adjacent sequences: A132955 A132956 A132957 * A132959 A132960 A132961
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KEYWORD
| easy,nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 06 2007
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 13 2007
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