G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^4)^3.

Terms

a(0) =1a(1) =1a(2) =3a(3) =15a(4) =79a(5) =468a(6) =2895a(7) =18670a(8) =123765a(9) =838860a(10) =5785503a(11) =40473729a(12) =286504086a(13) =2048388112a(14) =14770313397a(15) =107290913232a(16) =784380664232