\[ n y(x)+x y'(x)+y^{(3)}(x)=0 \] ✓ Mathematica : cpu = 0.0110457 (sec), leaf count = 103
\[\left \{\left \{y(x)\to \frac {c_3 x^2 \, _1F_2\left (\frac {n}{3}+\frac {2}{3};\frac {4}{3},\frac {5}{3};-\frac {x^3}{9}\right )}{3 \sqrt [3]{3}}+\frac {c_2 x \, _1F_2\left (\frac {n}{3}+\frac {1}{3};\frac {2}{3},\frac {4}{3};-\frac {x^3}{9}\right )}{3^{2/3}}+c_1 \, _1F_2\left (\frac {n}{3};\frac {1}{3},\frac {2}{3};-\frac {x^3}{9}\right )\right \}\right \}\] ✓ Maple : cpu = 0.095 (sec), leaf count = 58
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,{\mbox {$_1$F$_2$}({\frac {n}{3}};\,{\frac {1}{3}},{\frac {2}{3}};\,-{\frac {{x}^{3}}{9}})}+{\it \_C2}\,x{\mbox {$_1$F$_2$}({\frac {1}{3}}+{\frac {n}{3}};\,{\frac {2}{3}},{\frac {4}{3}};\,-{\frac {{x}^{3}}{9}})}+{\it \_C3}\,{x}^{2}{\mbox {$_1$F$_2$}({\frac {2}{3}}+{\frac {n}{3}};\,{\frac {4}{3}},{\frac {5}{3}};\,-{\frac {{x}^{3}}{9}})} \right \} \]