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A009058
Expansion of e.g.f. cos(sinh(x))/cos(x), even terms only.
1
1, 0, -4, -56, -1072, -34368, -1781440, -132000896, -12912385792, -1604411553792, -247155791205376, -46275148760619008, -10352111715031035904, -2727077778568910979072, -835562477291891829882880
OFFSET
0,3
LINKS
MAPLE
seq(coeff(series(factorial(n)*cos(sinh(x))/cos(x), x, n+1), x, n), n=0..40, 2); # Muniru A Asiru, Jul 24 2018
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 23 2018 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(cos(sinh(x))/cos(x))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 23 2018
CROSSREFS
Sequence in context: A327199 A358886 A371678 * A375817 A276363 A361541
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved