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%I #13 Jun 21 2015 21:49:30
%S 0,1,-2,9,-51,384,-3506,38126,-479770,6872392,-110410296,1967181840,
%T -38502498592,821352161200,-18969587297792,471608373782864,
%U -12558441874756176,356636706706414848,-10759204665600245888
%N Expansion of log(1+log(1+tan(x))).
%F a(n) ~ (n-1)! * (-1)^(n+1) / (arctan(1-exp(-1))^n). - _Vaclav Kotesovec_, Jan 22 2015
%t Log[ 1+Log[ 1+Tan[ x ] ] ]
%t CoefficientList[Series[Log[1 + Log[1 + Tan[x]]], {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 22 2015 *)
%K sign,easy
%O 0,3
%A _R. H. Hardin_
%E Extended with signs by _Olivier Gérard_, Mar 15 1997