\[ y(x) \left (y(x)^2+1\right ) y''(x)+\left (1-3 y(x)^2\right ) y'(x)^2=0 \] ✓ Mathematica : cpu = 0.518905 (sec), leaf count = 84
\[\left \{\left \{y(x)\to -\frac {\sqrt {-2 c_1 x-1-2 c_2 c_1}}{\sqrt {2} \sqrt {c_1 x+c_2 c_1}}\right \},\left \{y(x)\to \frac {\sqrt {-2 c_1 x-1-2 c_2 c_1}}{\sqrt {2} \sqrt {c_1 x+c_2 c_1}}\right \}\right \}\] ✓ Maple : cpu = 0.052 (sec), leaf count = 60
\[y \relax (x ) = -\frac {\sqrt {-4 \left (c_{1} x +c_{2}+\frac {1}{2}\right ) \left (c_{1} x +c_{2}\right )}}{2 c_{1} x +2 c_{2}}\]