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

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =0a(6) =4a(7) =9a(8) =5a(9) =22a(10) =78a(11) =91a(12) =175a(13) =680a(14) =1224a(15) =1938a(16) =6270a(17) =14630a(18) =24794a(19) =63756a(20) =166980a(21) =322920a(22) =720720a(23) =1900080a(24) =4125888a(25) =8803008a(26) =22151360a(27) =51778804a(28) =111882100a(29) =267682272