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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =4a(9) =9a(10) =5a(11) =0a(12) =22a(13) =78a(14) =91a(15) =35a(16) =140a(17) =680a(18) =1224a(19) =969a(20) =1254a(21) =5985a(22) =14630a(23) =17710a(24) =17710a(25) =55660a(26) =164450a(27) =269100a(28) =299520a(29) =593775