E.g.f. satisfies A(x) = 1 + x^2/2*exp(x*A(x)).

Terms

a(0) =1a(1) =0a(2) =1a(3) =3a(4) =6a(5) =40a(6) =375a(7) =2541a(8) =21028a(9) =264636a(10) =3303765a(11) =41219695a(12) =625493946a(13) =10676900598a(14) =185753808331