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 A009433 Expansion of e.g.f. log(1+x)/cosh(tan(x)). 3
 0, 1, -1, -1, 0, -11, 15, 27, -504, 11817, -94185, 1226455, -12442056, 155936221, -1995562569, 27870901107, -423463160400, 6793396567633, -117302680146033, 2130615128588591, -40960288523646320, 827190717641773765 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS G. C. Greubel, Table of n, a(n) for n = 0..448 FORMULA a(n) ~ (n-1)! * (-1)^(n+1) / cosh(tan(1)). - Vaclav Kotesovec, Jan 23 2015 MATHEMATICA With[{m=25}, CoefficientList[Series[Log[1+x]/Cosh[Tan[x]], {x, 0, m}], x]*Range[0, m]!] (* modified by G. C. Greubel, Sep 06 2023 *) CoefficientList[Series[Log[1 + x]*Sech[Tan[x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *) PROG (Magma) R:=PowerSeriesRing(Rationals(), 30); [0] cat Coefficients(R!(Laplace( Log(1+x)/Cosh(Tan(x)) ))); // G. C. Greubel, Sep 06 2023 (SageMath) def A009433_list(prec): P. = PowerSeriesRing(QQ, prec) return P( log(1+x)/cosh(tan(x)) ).egf_to_ogf().list() A009433_list(40) # G. C. Greubel, Sep 06 2023 (PARI) my(x='x+O('x^30)); concat([0], Vec(serlaplace(log(1+x)/cosh(tan(x))))) \\ Joerg Arndt, Sep 06 2023 CROSSREFS Cf. A009405 - A009420, A009422 - A009432, A009434 - A009439. Sequence in context: A214863 A094766 A009407 * A275242 A030099 A085597 Adjacent sequences: A009430 A009431 A009432 * A009434 A009435 A009436 KEYWORD sign,easy AUTHOR R. H. Hardin EXTENSIONS Extended with signs by Olivier Gérard, Mar 15 1997 STATUS approved

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Last modified September 13 20:16 EDT 2024. Contains 375910 sequences. (Running on oeis4.)