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

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =10a(5) =32a(6) =95a(7) =306a(8) =978a(9) =3235a(10) =10767a(11) =36470a(12) =124514a(13) =429648a(14) =1492944a(15) =5225700a(16) =18396350a(17) =65115694a(18) =231555165a(19) =826956617a(20) =2964543205a(21) =10664540170a(22) =38484972969a(23) =139281469165a(24) =505408580484