\[ \boxed { {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) =-{\frac { \left ( {x}^{2}+1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) }{{x}^{3}}}-{\frac {y \left ( x \right ) }{{x}^{4}}}=0} \]
Mathematica: cpu = 0.087011 (sec), leaf count = 76 \[ \left \{\left \{y(x)\to c_2 G_{1,2}^{2,0}\left (-\frac {1}{2 x^2}| \begin {array}{c} \frac {3}{2} \\ 0,0 \\ \end {array} \right )+c_1 e^{\frac {1}{4 x^2}} \left (\left (1-\frac {1}{2 x^2}\right ) I_0\left (\frac {1}{4 x^2}\right )+\frac {I_1\left (\frac {1}{4 x^2}\right )}{2 x^2}\right )\right \}\right \} \]
Maple: cpu = 0.063 (sec), leaf count = 73 \[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}}{{x}^{2}}{{\rm e}^{{ \frac {1}{4\,{x}^{2}}}}} \left ( \left ( 2\,{x}^{2}-1 \right ) {{\sl I} _{0}\left ({\frac {1}{4\,{x}^{2}}}\right )}+{{\sl I}_{1}\left ({\frac {1 }{4\,{x}^{2}}}\right )} \right ) }+{\frac {{\it \_C2}}{{x}^{2}}{{\rm e}^ {{\frac {1}{4\,{x}^{2}}}}} \left ( \left ( 2\,{x}^{2}-1 \right ) { {\sl K}_{0}\left (-{\frac {1}{4\,{x}^{2}}}\right )}+{{\sl K}_{1}\left (-{ \frac {1}{4\,{x}^{2}}}\right )} \right ) } \right \} \]