27175425004domain: NAppears in sequencesG.f. A(x) satisfies A(x) = 1 + x*A(x)^2*(A(x) + A(-x))/2.at n=18A217138G.f. A(x) satisfies A(x)^2 = 1 + 4*x*A(x)^6.at n=9A245113