25866752domain: NAppears in sequencesE.g.f.: Sum_{n >= 0} a(n) * x^(2*n) / (2*n)! = sin(x)^2 / cos(2*x).at n=5A000816E.g.f.: cos(x)^2 / cos(2x) = Sum_{n >= 0} a(n) * x^(2n) / (2n)!.at n=5A000819Expansion of (sin^2 x + sin x) /cos 2x.at n=10A000822E.g.f. cos(x)/(cos(x) - sin(x)).at n=10A000828