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A009094 Expansion of e.g.f. cos(tanh(x)*tan(x)) (only powers that are multiples of 4). 1
1, -12, -4592, -6274752, 18138366208, 2332645761266688, 202540305420145266688, 24977439274944176331767808, 4480212151308993274762821173248, 1107507319145672023044777103840247808, 336310686770623540666061200154740824997888 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
MATHEMATICA
With[{nn=60}, Select[CoefficientList[Series[Cos[Tanh[x]Tan[x]], {x, 0, nn}], x]Range[0, nn]!, #!=0&]] (* Harvey P. Dale, Dec 28 2012 *)
PROG
(PARI) x='x+O('x^80); v=Vec(serlaplace(cos(tanh(x)*tan(x)))); vector(#v\4, n, v[4*n-3]) \\ G. C. Greubel, Jul 25 2018
CROSSREFS
Sequence in context: A287889 A288967 A361106 * A061701 A236067 A134821
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved

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Last modified April 16 09:50 EDT 2024. Contains 371698 sequences. (Running on oeis4.)