login
A009746
Expansion of e.g.f. tan(x)*sinh(tan(x)), even powers only.
2
0, 2, 20, 438, 16680, 973034, 80252732, 8859646110, 1258403748432, 223202277906386, 48295209177888356, 12510350648500199814, 3820068667490198035320, 1357281805972469318509754
OFFSET
0,2
LINKS
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[Tan[x]*Sinh[Tan[x]], {x, 0, nmax} ], x]*Range[0, nmax]!][[1 ;; ;; 2]] (* G. C. Greubel, Feb 12 2018 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(tan(x)*sinh(tan(x)))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Feb 12 2018
CROSSREFS
Sequence in context: A058346 A165554 A366447 * A009749 A012533 A009160
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested by Olivier Gérard, Mar 15 1997
STATUS
approved