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A009366 Expansion of log(1+tan(tan(x))). 0

%I #13 Jun 22 2015 22:21:45

%S 0,1,-1,6,-22,176,-1192,12240,-122288,1561088,-20588544,318007808,

%T -5193155328,94807748608,-1841205505024,38942692972544,

%U -875204314126336,21088169713729536,-537861879179575296,14558790290337431552

%N Expansion of log(1+tan(tan(x))).

%F a(n) ~ (n-1)! * (-1)^(n+1) / (arctan(Pi/4))^n. - _Vaclav Kotesovec_, Jan 23 2015

%t Log[ 1+Tan[ Tan[ x ] ] ]

%t CoefficientList[Series[Log[1 + Tan[Tan[x]]], {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 23 2015 *)

%K sign,easy

%O 0,4

%A _R. H. Hardin_

%E Extended with signs by _Olivier GĂ©rard_, Mar 15 1997

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Last modified July 25 01:41 EDT 2024. Contains 374585 sequences. (Running on oeis4.)