78633536domain: NAppears in sequencesG.f.: A(x) = 1 + x*[A_2(x)]^2, where A_2(x) = 2 + x*[A_3(x)]^2, A_3(x) = 3 + x*[A_4(x)]^2, ..., A_n(x) = n + x*[A_{n+1}(x)]^2, ...at n=7A135906