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A009073 Expansion of e.g.f. cos(tan(x))/cosh(x), even terms only. 1
1, -2, 4, -128, 1296, -85600, 4372160, -148860416, 54261590272, 1474575037952, 1579094994228224, 145025202842173440, 87575771555229601792, 13290672132247757398016, 8077796113026531668901888 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Cos[Tan[x]]/Cosh[x], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Feb 12 2015 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(cos(tan(x))/cosh(x))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 24 2018
CROSSREFS
Sequence in context: A018493 A046035 A134710 * A326213 A369699 A012561
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Prior Mathematica program replaced by Harvey P. Dale, Feb 12 2015
STATUS
approved

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Last modified September 8 22:43 EDT 2024. Contains 375759 sequences. (Running on oeis4.)