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

Terms

a(0) =0a(1) =1a(2) =-1a(3) =-1a(4) =6a(5) =-11a(6) =0a(7) =83a(8) =-784a(9) =6921a(10) =-34560a(11) =-60281a(12) =2821632a(13) =-29132611a(14) =184690688a(15) =-208438245a(16) =-19939461120a(17) =427918448785