G.f. A(x,y) satisfies: A(x,y) = x*y + 1/A(x,x*y), with A(0,y) = 1.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =-1a(5) =0a(6) =1a(7) =0a(8) =-1a(9) =1a(10) =0a(11) =1a(12) =-2a(13) =0a(14) =-1a(15) =2a(16) =-1a(17) =0a(18) =1a(19) =-2a(20) =3a(21) =0a(22) =-1a(23) =3a(24) =-4a(25) =1a(26) =0a(27) =1a(28) =-4a(29) =5