Expansion of exp(tanh(tan(x))).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =-7a(6) =-47a(7) =-279a(8) =-1343a(9) =-5167a(10) =-8671a(11) =150833a(12) =2436545a(13) =27945609a(14) =249528945a(15) =1993449433a(16) =10176663169a(17) =-9028140255