\[ \boxed { \left ( {x}^{2}-1 \right ) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +4\,x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) + \left ( {x}^{2}+1 \right ) y \left ( x \right ) =0} \]
Mathematica: cpu = 0.029004 (sec), leaf count = 45 \[ \left \{\left \{y(x)\to \frac {c_1 e^{-i x}}{x^2-1}-\frac {i c_2 e^{i x}}{2 \left (x^2-1\right )}\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 27 \[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}\,\sin \left ( x \right ) }{{x}^{2}-1}}+{\frac {{\it \_C2}\,\cos \left ( x \right ) }{{x} ^{2}-1}} \right \} \]