E.g.f.: 1 / (2 + x^3/6 - exp(x)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =12a(4) =67a(5) =461a(6) =3823a(7) =36933a(8) =407963a(9) =5068909a(10) =69982083a(11) =1062784273a(12) =17607354955a(13) =316012688213