G.f. satisfies: A(x^2) = -4*x + 1/AGM(1, 1 - 8*x/(A(x^2) + 4*x) ).

Terms

a(0) =1a(1) =4a(2) =4a(3) =-16a(4) =-28a(5) =176a(6) =336a(7) =-2496a(8) =-4956a(9) =40112a(10) =81488a(11) =-694720a(12) =-1432688a(13) =12647488a(14) =26360896a(15) =-238598400a(16) =-501256668a(17) =4623092400a(18) =9772018896a(19) =-91458048960a(20) =-194263943664