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A009298
Expansion of e.g.f.: exp(x)/cosh(tanh(x)).
1
1, 1, 0, -2, 8, 56, -216, -2344, 12032, 168640, -1075328, -18467712, 140944000, 2863703168, -25464568832, -597301399296, 6065774456832, 161295676067840, -1842040163078144, -54752864215838720, 694620312112857088
OFFSET
0,4
LINKS
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Exp[x]/Cosh[Tanh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jun 26 2013 *)
CROSSREFS
Sequence in context: A117564 A254222 A023179 * A354175 A306087 A113248
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Definition clarified and prior Mathematica program replaced by Harvey P. Dale, Jun 26 2013
STATUS
approved