Expansion of exp(tanh(x))/cosh(x).

Terms

a(0) =1a(1) =1a(2) =0a(3) =-4a(4) =-8a(5) =32a(6) =216a(7) =-264a(8) =-7552a(9) =-9216a(10) =349568a(11) =1548032a(12) =-20281216a(13) =-190744448a(14) =1350879232a(15) =25395878400a(16) =-84211707904a(18) =-286327484416