\[ a \nu x^{\nu -1} y(x)+a x^{\nu } y'(x)+y^{(5)}(x)=0 \] ✓ Mathematica : cpu = 0.637165 (sec), leaf count = 528
\[\left \{\left \{y(x)\to \nu ^{-\frac {16}{\nu +4}} \left (\frac {\nu +4}{\nu }\right )^{-\frac {16}{\nu +4}} a^{\frac {1}{\nu +4}} \left (x^{\nu }\right )^{\frac {1}{\nu }} \left (a^{\frac {1}{\nu +4}} \left (x^{\nu }\right )^{\frac {1}{\nu }} \left (a^{\frac {1}{\nu +4}} \left (x^{\nu }\right )^{\frac {1}{\nu }} \left (c_5 a^{\frac {1}{\nu +4}} \left (x^{\nu }\right )^{\frac {1}{\nu }} \, _1F_4\left (1;\frac {\nu }{\nu +4}+\frac {5}{\nu +4},\frac {\nu }{\nu +4}+\frac {6}{\nu +4},\frac {\nu }{\nu +4}+\frac {7}{\nu +4},\frac {\nu }{\nu +4}+\frac {8}{\nu +4};-\frac {a \left (x^{\nu }\right )^{\frac {\nu +4}{\nu }}}{(\nu +4)^4}\right )+c_4 \nu ^{\frac {4}{\nu +4}} \left (\frac {\nu +4}{\nu }\right )^{\frac {4}{\nu +4}} \, _0F_3\left (;\frac {\nu }{\nu +4}+\frac {5}{\nu +4},\frac {\nu }{\nu +4}+\frac {6}{\nu +4},\frac {\nu }{\nu +4}+\frac {7}{\nu +4};-\frac {a \left (x^{\nu }\right )^{\frac {\nu +4}{\nu }}}{(\nu +4)^4}\right )\right )+c_3 \nu ^{\frac {8}{\nu +4}} \left (\frac {\nu +4}{\nu }\right )^{\frac {8}{\nu +4}} \, _0F_3\left (;\frac {\nu }{\nu +4}+\frac {3}{\nu +4},\frac {\nu }{\nu +4}+\frac {5}{\nu +4},\frac {\nu }{\nu +4}+\frac {6}{\nu +4};-\frac {a \left (x^{\nu }\right )^{\frac {\nu +4}{\nu }}}{(\nu +4)^4}\right )\right )+c_2 \nu ^{\frac {12}{\nu +4}} \left (\frac {\nu +4}{\nu }\right )^{\frac {12}{\nu +4}} \, _0F_3\left (;\frac {\nu }{\nu +4}+\frac {2}{\nu +4},\frac {\nu }{\nu +4}+\frac {3}{\nu +4},\frac {\nu }{\nu +4}+\frac {5}{\nu +4};-\frac {a \left (x^{\nu }\right )^{\frac {\nu +4}{\nu }}}{(\nu +4)^4}\right )\right )+c_1 \, _0F_3\left (;\frac {\nu }{\nu +4}+\frac {1}{\nu +4},\frac {\nu }{\nu +4}+\frac {2}{\nu +4},\frac {\nu }{\nu +4}+\frac {3}{\nu +4};-\frac {a \left (x^{\nu }\right )^{\frac {\nu +4}{\nu }}}{(\nu +4)^4}\right )\right \}\right \}\]
✗ Maple : cpu = 0. (sec), leaf count = 0 , result contains DESol
\[ \left \{ y \left ( x \right ) ={\it DESol} \left ( \left \{ {\frac {{\rm d}^{5}}{{\rm d}{x}^{5}}}{\it \_Y} \left ( x \right ) +a{x}^{\nu }{\frac {\rm d}{{\rm d}x}}{\it \_Y} \left ( x \right ) +a\nu \,{x}^{\nu -1}{\it \_Y} \left ( x \right ) \right \} , \left \{ {\it \_Y} \left ( x \right ) \right \} \right ) \right \} \]