\[ \boxed { x{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +ay \left ( x \right ) =0} \]
Mathematica: cpu = 0.022003 (sec), leaf count = 41 \[ \left \{\left \{y(x)\to c_1 J_0\left (2 \sqrt {a} \sqrt {x}\right )+2 c_2 Y_0\left (2 \sqrt {a} \sqrt {x}\right )\right \}\right \} \]
Maple: cpu = 0.016 (sec), leaf count = 29 \[ \left \{ y \left ( x \right ) ={\it \_C1}\,{{\sl J}_{0}\left (2\,\sqrt {a }\sqrt {x}\right )}+{\it \_C2}\,{{\sl Y}_{0}\left (2\,\sqrt {a}\sqrt {x} \right )} \right \} \]