DSolve[(1 + 6*x + 8*x^2 + 4*x^3 + x^4)*y[x] + (-2 - 12*x - 15*x^2 - 6*x^3 + x^6)*Derivative[1][y][x] - (-1 - 6*x - 6*x^2 + 3*x^4 + 2*x^6)*Derivative[2][y][x] + x^2*(1 + 2*x + 2*x^2 + x^4)*Derivative[3][y][x] == 0,y[x],x]