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A009319
Expansion of log(1+log(1+x)*cos(x)).
0
0, 1, -2, 4, -17, 93, -649, 5381, -51778, 565957, -6930141, 93992413, -1399244076, 22689478823, -398164266655, 7519118564551, -152058873978384, 3278894568674073, -75103386737309385, 1821102601528126265
OFFSET
0,3
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) / r^n, where r = 0.7426973079865501887067225087448265047287233394318... is the root of the equation exp(1/cos(r))*(r-1) = -1. - Vaclav Kotesovec, Jan 24 2015
MATHEMATICA
Log[ 1+Log[ 1+x ]*Cos[ x ] ]
CoefficientList[Series[Log[1 + Cos[x]*Log[1 + x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 24 2015 *)
CROSSREFS
Sequence in context: A112005 A212581 A305786 * A347724 A009323 A307125
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved