\[ \boxed { x{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +2\,{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +axy \left ( x \right ) =0} \]
Mathematica: cpu = 0.025503 (sec), leaf count = 51 \[ \left \{\left \{y(x)\to \frac {c_1 e^{-\sqrt {-a} x}}{x}+\frac {c_2 e^{\sqrt {-a} x}}{2 \sqrt {-a} x}\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 31 \[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}}{x}\sinh \left ( \sqrt {-a}x \right ) }+{\frac {{\it \_C2}}{x}\cosh \left ( \sqrt {-a}x \right ) } \right \} \]