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