\[ -n y(x)+y^{(3)}(x)-x y'(x)=0 \] ✓ Mathematica : cpu = 0.009509 (sec), leaf count = 113
DSolve[-(n*y[x]) - x*Derivative[1][y][x] + Derivative[3][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to \frac {\sqrt [3]{-1} c_2 x \, _1F_2\left (\frac {n}{3}+\frac {1}{3};\frac {2}{3},\frac {4}{3};\frac {x^3}{9}\right )}{3^{2/3}}+c_1 \, _1F_2\left (\frac {n}{3};\frac {1}{3},\frac {2}{3};\frac {x^3}{9}\right )+\frac {(-1)^{2/3} c_3 x^2 \, _1F_2\left (\frac {n}{3}+\frac {2}{3};\frac {4}{3},\frac {5}{3};\frac {x^3}{9}\right )}{3 \sqrt [3]{3}}\right \}\right \}\] ✓ Maple : cpu = 0.05 (sec), leaf count = 58
dsolve(diff(diff(diff(y(x),x),x),x)-x*diff(y(x),x)-n*y(x)=0,y(x))
\[y \left (x \right ) = c_{1} \operatorname {hypergeom}\left (\left [\frac {n}{3}\right ], \left [\frac {1}{3}, \frac {2}{3}\right ], \frac {x^{3}}{9}\right )+c_{2} x \operatorname {hypergeom}\left (\left [\frac {1}{3}+\frac {n}{3}\right ], \left [\frac {2}{3}, \frac {4}{3}\right ], \frac {x^{3}}{9}\right )+c_{3} x^{2} \operatorname {hypergeom}\left (\left [\frac {2}{3}+\frac {n}{3}\right ], \left [\frac {4}{3}, \frac {5}{3}\right ], \frac {x^{3}}{9}\right )\]