\[ \boxed { {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) - \left ( y \left ( x \right ) \right ) ^{2}=0} \]
Mathematica: cpu = 0.039005 (sec), leaf count = 26 \[ \left \{\left \{y(x)\to \sqrt [3]{6} \wp \left (\frac {x+c_1}{\sqrt [3]{6}};0,c_2\right )\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 12 \[ \left \{ y \left ( x \right ) =6\,{\it WeierstrassP} \left ( x+{\it \_C1} ,0,{\it \_C2} \right ) \right \} \]