\[ \boxed { x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +ay \left ( x \right ) +b{x}^{n}=0} \]
Mathematica: cpu = 0.013502 (sec), leaf count = 25 \[ \left \{\left \{y(x)\to c_1 x^{-a}-\frac {b x^n}{a+n}\right \}\right \} \]
Maple: cpu = 0.0 (sec), leaf count = 23 \[ \left \{ y \left ( x \right ) =-{\frac {b{x}^{n}}{n+a}}+{x}^{-a}{\it \_C1} \right \} \]