\[ \boxed { {x}^{2}{\it d4y} \left ( x \right ) +6\,x{\frac {{\rm d}^{3}}{{\rm d}{x}^{3}}}y \left ( x \right ) +6\,{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) -{\lambda }^{2}y \left ( x \right ) =0} \]
Mathematica: cpu = 0.060008 (sec), leaf count = 156 \[ \left \{\left \{y(x)\to c_4 G_{0,4}^{2,0}\left (\frac {\lambda ^2 x^2}{16}| \begin {array}{c} -\frac {1}{2},\frac {1}{2},0,0 \\ \end {array} \right )+c_2 G_{0,4}^{2,0}\left (\frac {\lambda ^2 x^2}{16}| \begin {array}{c} 0,0,-\frac {1}{2},\frac {1}{2} \\ \end {array} \right )+\frac {c_1 \left (J_1\left (2 \sqrt {\lambda } \sqrt {x}\right )+I_1\left (2 \sqrt {\lambda } \sqrt {x}\right )\right )}{2 \sqrt {\lambda } \sqrt {x}}-\frac {i c_3 \left (I_1\left (2 \sqrt {\lambda } \sqrt {x}\right )-J_1\left (2 \sqrt {\lambda } \sqrt {x}\right )\right )}{4 \sqrt {\lambda } \sqrt {x}}\right \}\right \} \]
Maple: cpu = 0.062 (sec), leaf count = 69 \[ \left \{ y \left ( x \right ) ={{\it \_C1}{{\sl J}_{1}\left (2\,\sqrt { \lambda }\sqrt {x}\right )}{\frac {1}{\sqrt {x}}}}+{{\it \_C2}{{\sl Y}_{ 1}\left (2\,\sqrt {\lambda }\sqrt {x}\right )}{\frac {1}{\sqrt {x}}}}+{{ \it \_C3}{{\sl J}_{1}\left (2\,\sqrt {-\lambda }\sqrt {x}\right )}{\frac {1}{\sqrt {x}}}}+{{\it \_C4}{{\sl Y}_{1}\left (2\,\sqrt {-\lambda } \sqrt {x}\right )}{\frac {1}{\sqrt {x}}}} \right \} \]