Expansion of e.g.f. log(1 + tan(x)).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =4a(4) =-14a(5) =80a(6) =-496a(7) =3904a(8) =-34544a(9) =354560a(10) =-4055296a(11) =51733504a(12) =-724212224a(13) =11070525440a(14) =-183218384896