A009387 - OEIS

%I #17 Jun 22 2015 22:28:22

%S 0,1,-1,-2,10,16,-232,-272,10064,7936,-720384,-353792,78009600,

%T 22368256,-11977120768,-1903757312,2480763381760,209865342976,

%U -666957211828224,-29088885112832,225809770695098368,4951498053124096

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

%t With[{nn=30},CoefficientList[Series[Log[1+ Tanh[ Tanh[x]]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Aug 08 2012 *)

%Y Cf. A000182.

%Y Bisections are A000182 and A012240.

%K sign,easy

%O 0,4

%A _R. H. Hardin_

%E Extended with signs by _Olivier Gérard_, Mar 15 1997