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

Terms

a(0) =1a(1) =0a(2) =-2a(3) =3a(4) =1a(5) =10a(6) =-176a(7) =735a(8) =-1707a(9) =18828a(10) =-251646a(11) =1819895a(12) =-10653939a(13) =114938382a(14) =-1464499076a(15) =11843786955a(16) =-40962861815a(17) =-513203638440