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

Terms

a(0) =0a(1) =1a(2) =-1a(3) =0a(4) =-4a(5) =40a(6) =-181a(7) =896a(8) =-8464a(9) =88320a(10) =-863041a(11) =9382912a(12) =-120330244a(13) =1676579840a(14) =-24638823301a(15) =390142722048