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A009320
Expansion of log(1+log(1+x)*cosh(x)).
0
0, 1, -2, 10, -53, 373, -3289, 34543, -421994, 5884933, -92255061, 1606210571, -30754222080, 642299748231, -14531152719875, 354020726656465, -9240813172692064, 257285058656341145, -7611049992188970105
OFFSET
0,3
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) / (1-exp(-r))^n, where r = 0.8549045967031373719104055170906807819800761165... is the root of the equation 2*exp(-1 + exp(-r)) - r - exp(2/exp(r)-2)*r = 0. - Vaclav Kotesovec, Jan 24 2015
MATHEMATICA
Log[ 1+Log[ 1+x ]*Cosh[ x ] ]
CoefficientList[Series[Log[1 + Cosh[x]*Log[1 + x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 24 2015 *)
CROSSREFS
Sequence in context: A221610 A247102 A370390 * A204186 A009322 A192697
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved