DSolve[Derivative[2][y][x] == -(((-m^2 - n*(1 + n)*(-1 + x^2) - a^2*(-1 + x^2)^2)*y[x])/(-1 + x^2)^2) - (2*x*Derivative[1][y][x])/(-1 + x^2),y[x],x]