\left(x \left(-\rho ^2-\sigma ^2+1\right)+16 x^3\right) y'(x)+y(x) \left(\rho ^2 \sigma ^2+8 x^2\right)+\left(x^2 \left(-\rho ^2-\sigma ^2+7\right)+4 x^4\right) y''(x)+x^4 y^{(4)}(x)+6 x^3 y^{(3)}(x)=0