E.g.f.: 1/(cos(x) - sin(x)*cosh(x)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =14a(4) =81a(5) =596a(6) =5283a(7) =54424a(8) =641281a(9) =8502736a(10) =125240163a(11) =2029253984a(12) =35869368081a(13) =686861235776