

A009082


Expansion of e.g.f. cos(tan(x)/cosh(x)), even terms only.


1



1, 1, 5, 157, 3817, 257049, 15886125, 1844058101, 218349214545, 38729647296945, 7468216325125589, 1882371895493492429, 533348579359954590009, 181834605583994802568393
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OFFSET

0,3


LINKS



MATHEMATICA

With[{nmax = 60}, CoefficientList[Series[Cos[Tan[x]/Cosh[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(tan(x)/cosh(x)))); vector(#v\2, n, v[2*n1]) \\ G. C. Greubel, Jul 24 2018


CROSSREFS



KEYWORD

sign


AUTHOR



EXTENSIONS



STATUS

approved



