OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..240
FORMULA
a(n) = (2*n+1)! * [x^(2*n+1)] cos(tan(x))*x. - Alois P. Heinz, Oct 01 2012
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[Cos[Tan[x]]*x, {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Oct 01 2012 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(x*cos(tan(x)))); vector((#v-1)\2 , n, v[2*n-1]) \\ G. C. Greubel, Jul 24 2018
CROSSREFS
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
More terms from Harvey P. Dale, Oct 01 2012
STATUS
approved