A009245 - OEIS

A009245

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

1, 1, 0, 0, 8, 32, 56, 280, 3968, 27520, 133248, 1072896, 13993088, 137702528, 1139191808, 12544190464, 178943504384, 2268209053696, 26439024316416, 366953307820032, 5943319707680768, 91839717688770560

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OFFSET

0,5

LINKS

Table of n, a(n) for n=0..21.

MATHEMATICA

With[{nn=30}, CoefficientList[Series[Exp[Tan[x]]/Cosh[x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, May 01 2016 *)

CROSSREFS

Sequence in context: A067519 A253295 A290960 * A018842 A139098 A224543

Adjacent sequences: A009242 A009243 A009244 * A009246 A009247 A009248

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended and signs tested Mar 15 1997 by Olivier Gérard.

Previous Mathematica program replaced by Harvey P. Dale, May 01 2016

STATUS

approved