G.f. satisfies: A(x) = 1 + x^2 + x^2*A'(x)/A(x).

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =6a(5) =22a(6) =100a(7) =554a(8) =3654a(9) =28014a(10) =244572a(11) =2392042a(12) =25877610a(13) =306553246a(14) =3944541224a(15) =54764396346a(16) =815786104186