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A009064
Expansion of e.g.f. cos(sinh(x)/cos(x)), even powers only.
1
1, -1, -15, -297, -6783, -70609, 18558705, 4027228359, 727421677185, 134584692783455, 26232888936219249, 5245335359878123191, 971782758809341914369, 96545317222649153850767
OFFSET
0,3
LINKS
MATHEMATICA
With[{nmax = 60}, CoefficientList[Series[Cos[Sinh[x]/Cos[x]], {x, 0, nmax}], x]*Range[0, nmax]!][[1 ;; -1 ;; 2]] (* G. C. Greubel, Jul 24 2018 *)
PROG
(PARI) x='x+O('x^60); v=Vec(serlaplace(cos(sinh(x)/cos(x)))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 24 2018
CROSSREFS
Sequence in context: A201341 A144349 A375222 * A049381 A051691 A247238
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved