A009297 Expansion of exp(x)/cosh(tan(x)).

1, 1, 0, -2, -8, -24, -56, -104, 512, 5824, 54912, 385408, 2590336, 15920256, 69311488, 160063744, -3936710656, -67251703808, -914002857984, -9821117788160, -81770855727104, -551206277726208, 2175764106870784, 106679023552528384

Offset

0,4

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Mathematica

With[{nn=30}, CoefficientList[Series[Exp[x]/Cosh[Tan[x]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Apr 22 2012 *)

Crossrefs

Cf. A009107.

Sequence in context: A152132 A330520 A009059 * A235793 A182736 A083553

Adjacent sequences: A009294 A009295 A009296 * A009298 A009299 A009300

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved