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

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =10a(5) =46a(6) =244a(7) =1481a(8) =10020a(9) =74400a(10) =599573a(11) =5200284a(12) =48223360a(13) =475557054a(14) =4965035754a(15) =54672110310a(16) =632853655686