\[ \boxed { {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +y \left ( x \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) - \left ( y \left ( x \right ) \right ) ^{3}=0} \]
Mathematica: cpu = 122.323033 (sec), leaf count = 24 \[ \text {DSolve}\left [y''(x)+y(x) y'(x)-y(x)^3=0,y(x),x\right ] \]
Maple: cpu = 0.078 (sec), leaf count = 253 \[ \left \{ \int ^{y \left ( x \right ) }\! \left ( {\frac {{{\it \_a}}^{2} }{2}}+{\frac {1}{2} \left ( \sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6} +{{\it \_C1}}^{2}}}-{{{\it \_a}}^{2}{\frac {1}{\sqrt [3]{{\it \_C1}+ \sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}}}} \right ) ^{2}} \right ) ^{- 1}{d{\it \_a}}-x-{\it \_C2}=0,\int ^{y \left ( x \right ) }\! \left ( { \frac {{{\it \_a}}^{2}}{2}}+{\frac {1}{2} \left ( -{\frac {1}{2}\sqrt [ 3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}}+{\frac {{{ \it \_a}}^{2}}{2}{\frac {1}{\sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6 }+{{\it \_C1}}^{2}}}}}}-{\frac {i}{2}}\sqrt {3} \left ( \sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}+{{{\it \_a}}^{2}{ \frac {1}{\sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2} }}}}} \right ) \right ) ^{2}} \right ) ^{-1}{d{\it \_a}}-x-{\it \_C2}=0, \int ^{y \left ( x \right ) }\! \left ( {\frac {{{\it \_a}}^{2}}{2}}+{ \frac {1}{2} \left ( -{\frac {1}{2}\sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}}+{\frac {{{\it \_a}}^{2}}{2}{\frac {1}{ \sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}}}}+{ \frac {i}{2}}\sqrt {3} \left ( \sqrt [3]{{\it \_C1}+\sqrt {{{\it \_a}}^ {6}+{{\it \_C1}}^{2}}}+{{{\it \_a}}^{2}{\frac {1}{\sqrt [3]{{\it \_C1} +\sqrt {{{\it \_a}}^{6}+{{\it \_C1}}^{2}}}}}} \right ) \right ) ^{2}} \right ) ^{-1}{d{\it \_a}}-x-{\it \_C2}=0 \right \} \]