Expansion of e.g.f.: exp(x)*sec(2*x).

Terms

a(0) =1a(1) =1a(2) =5a(3) =13a(4) =105a(5) =441a(6) =5165a(7) =30213a(8) =469585a(9) =3529201a(10) =68525525a(11) =629401213a(12) =14664091065a(13) =159175688361