\[ a^4 \left (-x^3\right ) y(x)+2 x^2 y^{(3)}(x)+x^3 y^{(4)}(x)+y'(x)-x y''(x)=0 \] ✓ Mathematica : cpu = 0.199824 (sec), leaf count = 100
\[\left \{\left \{y(x)\to c_4 G_{0,4}^{2,0}\left (\frac {a^4 x^4}{256}|\begin {array}{c} 0,0,\frac {1}{2},\frac {1}{2} \\\end {array}\right )+c_2 G_{0,4}^{2,0}\left (\frac {a^4 x^4}{256}|\begin {array}{c} \frac {1}{2},\frac {1}{2},0,0 \\\end {array}\right )+\frac {1}{8} i c_1 (I_0(a x)-J_0(a x))+\frac {1}{2} c_3 (J_0(a x)+I_0(a x))\right \}\right \}\] ✓ Maple : cpu = 0.122 (sec), leaf count = 33
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,{{\sl I}_{0}\left (ax\right )}+{\it \_C2}\,{{\sl J}_{0}\left (ax\right )}+{\it \_C3}\,{{\sl K}_{0}\left (ax\right )}+{\it \_C4}\,{{\sl Y}_{0}\left (ax\right )} \right \} \]