OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..50
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[Cosh[ArcTanh[x]ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 4}]] (* Harvey P. Dale, May 31 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
More terms from and definition clarified by Harvey P. Dale, May 31 2014
STATUS
approved