8856035370domain: NAppears in sequencesE.g.f. C(x) satisfies: C(x)^2 + 2*S(x)^2 = 1 such that S'(x) = C(x)^2 - S(x)*C(x) and C'(x) = 2*S(x)^2 - 2*S(x)*C(x), where S(x) is described by A279842.at n=13A279841