\[ \boxed { \left ( {x}^{2}+1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +xy \left ( x \right ) -x \left ( {x}^{2}+1 \right ) =0} \]
Mathematica: cpu = 0.011001 (sec), leaf count = 27 \[ \left \{\left \{y(x)\to \frac {c_1}{\sqrt {x^2+1}}+\frac {1}{3} \left (x^2+1\right )\right \}\right \} \]
Maple: cpu = 0.0 (sec), leaf count = 20 \[ \left \{ y \left ( x \right ) ={\frac {{x}^{2}}{3}}+{\frac {1}{3}}+{{ \it \_C1}{\frac {1}{\sqrt {{x}^{2}+1}}}} \right \} \]