E.g.f.: (sec(x) - tan(x)) / (2 - exp(x)).

Terms

a(0) =1a(1) =0a(2) =2a(3) =5a(4) =38a(5) =245a(6) =2232a(7) =22045a(8) =256958a(9) =3321945a(10) =48017612a(11) =761377685a(12) =13186155578a(13) =247266049745