G.f. satisfies: A(x,y) = 1-x + y*x + Series_Reversion( x/A(x,y)^2 ).

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =2a(5) =0a(6) =0a(7) =4a(8) =5a(9) =0a(10) =0a(11) =8a(12) =38a(13) =14a(14) =0a(15) =0a(16) =16a(17) =184a(18) =262a(19) =42a(20) =0a(21) =0a(22) =32a(23) =720a(24) =2460a(25) =1602a(26) =132a(27) =0a(28) =0a(29) =64