-812295domain: ZAppears in sequencesExpansion of e.g.f. S(x,k) satisfying S(x,k) = sin( x*cos(k*x*sqrt(1 - S(x,k)^2)) ), as a triangle read by rows.at n=16A370331Expansion of e.g.f. T(x,k) satisfying T(x,k) = (1/k) * sin( k*x*cos(x*sqrt(1 - k^2*T(x,k)^2)) ), as a triangle read by rows.at n=19A370333