\[ y''(x)=\frac {y'(x)}{x}-\frac {a y(x)}{x^6} \] ✓ Mathematica : cpu = 0.0876702 (sec), leaf count = 60
\[\left \{\left \{y(x)\to c_1 x^2 e^{\frac {i \sqrt {a}}{2 x^2}}-\frac {i c_2 x^2 e^{-\frac {i \sqrt {a}}{2 x^2}}}{2 \sqrt {a}}\right \}\right \}\] ✓ Maple : cpu = 0.088 (sec), leaf count = 35
\[ \left \{ y \left ( x \right ) ={x}^{2} \left ( \cosh \left ( {\frac {1}{2\,{x}^{2}}\sqrt {-a}} \right ) {\it \_C2}+\sinh \left ( {\frac {1}{2\,{x}^{2}}\sqrt {-a}} \right ) {\it \_C1} \right ) \right \} \]