\[ x^4 y'(x)-x^3 y(x)+y''(x)=0 \] ✓ Mathematica : cpu = 0.0531639 (sec), leaf count = 39
\[\left \{\left \{y(x)\to c_1 x-\frac {c_2 \sqrt [5]{x^5} \Gamma \left (-\frac {1}{5},\frac {x^5}{5}\right )}{5 \sqrt [5]{5}}\right \}\right \}\] ✓ Maple : cpu = 0.106 (sec), leaf count = 56
\[ \left \{ y \left ( x \right ) ={\frac {1}{{x}^{7}} \left ( 9\,{\it \_C2}\,{{\rm e}^{-1/10\,{x}^{5}}} \left ( {x}^{5}+4 \right ) {{\sl M}_{7/5,\,{\frac {9}{10}}}\left (1/5\,{x}^{5}\right )}+{x}^{8} \left ( {x}^{2}{\it \_C2}\,{{\rm e}^{-{\frac {{x}^{5}}{10}}}}{{\sl M}_{{\frac {2}{5}},\,{\frac {9}{10}}}\left ({\frac {{x}^{5}}{5}}\right )}+{\it \_C1} \right ) \right ) } \right \} \]