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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..19.

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

Adjacent sequences:  A009345 A009346 A009347 * A009349 A009350 A009351

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

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

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Last modified August 6 12:33 EDT 2020. Contains 336246 sequences. (Running on oeis4.)