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

Terms

a(0) =1a(1) =1a(2) =5a(3) =27a(4) =161a(5) =1030a(6) =6921a(7) =48190a(8) =344669a(9) =2517303a(10) =18695908a(11) =140771477a(12) =1072130229a(13) =8244820518a(14) =63931532190a(15) =499308229278