OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..242
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[Tan[x]/Cos[Tanh[x]], {x, 0, nn}], x]*Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Dec 08 2012 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(tan(x)/cos(tanh(x)))); vector((#v-1)\2 , n, v[2*n-1]) \\ G. C. Greubel, Feb 12 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested by Olivier Gérard, Mar 15 1997
More terms from Harvey P. Dale, Dec 08 2012
STATUS
approved