\[ \boxed { {x}^{2}{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +ay \left ( x \right ) =0} \]
Mathematica: cpu = 0.008501 (sec), leaf count = 30 \[ \left \{\left \{y(x)\to c_2 \sin \left (\sqrt {a} \log (x)\right )+c_1 \cos \left (\sqrt {a} \log (x)\right )\right \}\right \} \]
Maple: cpu = 0.016 (sec), leaf count = 23 \[ \left \{ y \left ( x \right ) ={\it \_C1}\,\sin \left ( \sqrt {a}\ln \left ( x \right ) \right ) +{\it \_C2}\,\cos \left ( \sqrt {a}\ln \left ( x \right ) \right ) \right \} \]