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A009415
Expansion of log(1+x)*cosh(tanh(x)).
0
0, 1, -1, 5, -12, 9, -105, 1413, -8176, 42801, -442665, 5165445, -54556524, 637139385, -8293744641, 113478922053, -1717525727040, 28284932778977, -475222905120177, 8340834063368709, -159725733100784940, 3244894614657423849
OFFSET
0,4
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) * cosh(tanh(1)). - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
Log[ 1+x ]*Cosh[ Tanh[ x ] ]
CoefficientList[Series[Cosh[Tanh[x]]*Log[1 + x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)
CROSSREFS
Sequence in context: A070368 A066326 A015242 * A251935 A195031 A265028
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved