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A009348
Expansion of e.g.f.: log(1+sinh(tan(x))).
0
0, 1, -1, 5, -18, 121, -792, 7013, -66640, 752785, -9320704, 129763589, -1972346112, 32812992265, -590188526592, 11441858264741, -237543276488704, 5261501926546081, -123809000924250112, 3084889329990554117
OFFSET
0,4
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) / arctan(log(1+sqrt(2)))^n. - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Log[1+Sinh[Tan[x]]], {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Jul 10 2014 *)
CROSSREFS
Sequence in context: A302435 A332467 A036688 * A009365 A140296 A278172
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, Jul 10 2014
STATUS
approved