Expansion of 1/sqrt(1-4*x*y-4*x^2*y).

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =2a(5) =6a(6) =0a(7) =0a(8) =12a(9) =20a(10) =0a(11) =0a(12) =6a(13) =60a(14) =70a(15) =0a(16) =0a(17) =0a(18) =60a(19) =280a(20) =252a(21) =0a(22) =0a(23) =0a(24) =20a(25) =420a(26) =1260a(27) =924a(28) =0a(29) =0