Expansion of log(1+sin(x)/cosh(x)).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =-2a(4) =10a(5) =-20a(6) =-16a(7) =488a(8) =-4080a(9) =22160a(10) =-7936a(11) =-1616672a(12) =22996480a(13) =-172976960a(14) =-22368256a(15) =25518205568a(16) =-485458114560a(18) =-209865342976