DSolve[-2*n*(1 - 2*m + 2*x)*y[x] + (m*(-1 + 2*m) + 4*(-m + n)*x + 2*x^2)*Derivative[1][y][x] - 3*x*(-m + x)*Derivative[2][y][x] + x^2*Derivative[3][y][x] == 0,y[x],x]