\[ y''(x)=\frac {y'(x)}{x}-\frac {a y(x)}{x^6} \] ✓ Mathematica : cpu = 0.0516633 (sec), leaf count = 60
\[\left \{\left \{y(x)\to c_1 x^2 e^{\frac {\sqrt {-a}}{2 x^2}}+\frac {c_2 x^2 e^{-\frac {\sqrt {-a}}{2 x^2}}}{2 \sqrt {-a}}\right \}\right \}\]
✓ Maple : cpu = 0.061 (sec), leaf count = 37
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,{x}^{2}\sinh \left ( {\frac {1}{2\,{x}^{2}}\sqrt {-a}} \right ) +{\it \_C2}\,{x}^{2}\cosh \left ( {\frac {1}{2\,{x}^{2}}\sqrt {-a}} \right ) \right \} \]