Expansion of exp(x)/cos(tan(x)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =20a(5) =76a(6) =608a(7) =3256a(8) =34320a(9) =235408a(10) =3084640a(11) =25823744a(12) =405224896a(13) =4007103296a(14) =73292662784a(15) =836059707008