Expansion of log(1+tan(x))*cos(x).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =1a(4) =-8a(5) =45a(6) =-301a(7) =2357a(8) =-21608a(9) =223769a(10) =-2602081a(11) =33484713a(12) =-473210528a(13) =7282225093a(14) =-121272163741