G.f. satisfies: A(x) = 1/AGM(1, 1 - 8*x/A(x) ).

Terms

a(0) =1a(1) =4a(2) =4a(3) =0a(4) =4a(5) =0a(6) =-16a(7) =0a(8) =-28a(9) =0a(10) =176a(11) =0a(12) =336a(13) =0a(14) =-2496a(15) =0a(16) =-4956a(17) =0a(18) =40112a(19) =0a(20) =81488a(21) =0a(22) =-694720a(23) =0a(24) =-1432688a(25) =0a(26) =12647488a(27) =0a(28) =26360896a(29) =0