G.f. A(x) satisfies A(x) = 1 + x*(1+x^2)^2*A(x)^3.

Terms

a(0) =1a(1) =1a(2) =3a(3) =14a(4) =67a(5) =346a(6) =1886a(7) =10662a(8) =61951a(9) =367728a(10) =2220254a(11) =13593162a(12) =84190978a(13) =526573057a(14) =3321150182a(15) =21099247736a(16) =134895625603a(17) =867272099089