\[ \left (x^2-1\right ) y''(x)+\left (x^2+1\right ) y(x)+4 x y'(x)=0 \] ✓ Mathematica : cpu = 0.032408 (sec), leaf count = 41
\[\left \{\left \{y(x)\to \frac {e^{-i x} \left (2 c_1-i c_2 e^{2 i x}\right )}{2 \left (x^2-1\right )}\right \}\right \}\]
✓ Maple : cpu = 0.074 (sec), leaf count = 21
\[ \left \{ y \left ( x \right ) ={\frac {{\it \_C2}\,\cos \left ( x \right ) +{\it \_C1}\,\sin \left ( x \right ) }{{x}^{2}-1}} \right \} \]