\[ \boxed { 4\, \left ( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) \right ) y \left ( x \right ) -3\, \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}-12\, \left ( y \left ( x \right ) \right ) ^{3}=0} \]
Mathematica: cpu = 0.547069 (sec), leaf count = 181 \[ \left \{\left \{y(x)\to \text {InverseFunction}\left [-\frac {4 \sqrt {\frac {4 \text {$\#$1}^{3/2}}{c_1}+1} \sqrt {\text {$\#$1}^{3/2} c_1+4 \text {$\#$1}^3} \, _2F_1\left (\frac {1}{6},\frac {1}{2};\frac {7}{6};-\frac {4 \text {$\#$1}^{3/2}}{c_1}\right )}{4 \text {$\#$1}^2+\sqrt {\text {$\#$1}} c_1}\& \right ]\left [c_2+x\right ]\right \},\left \{y(x)\to \text {InverseFunction}\left [\frac {4 \sqrt {\frac {4 \text {$\#$1}^{3/2}}{c_1}+1} \sqrt {\text {$\#$1}^{3/2} c_1+4 \text {$\#$1}^3} \, _2F_1\left (\frac {1}{6},\frac {1}{2};\frac {7}{6};-\frac {4 \text {$\#$1}^{3/2}}{c_1}\right )}{4 \text {$\#$1}^2+\sqrt {\text {$\#$1}} c_1}\& \right ]\left [c_2+x\right ]\right \}\right \} \]
Maple: cpu = 1.684 (sec), leaf count = 57 \[ \left \{ \int ^{y \left ( x \right ) }\!{\frac {1}{\sqrt {{\it \_C1}\,{{ \it \_a}}^{{\frac {3}{2}}}+4\,{{\it \_a}}^{3}}}}{d{\it \_a}}-x-{\it \_C2}=0,\int ^{y \left ( x \right ) }\!-{\frac {1}{\sqrt {{\it \_C1}\,{{ \it \_a}}^{{\frac {3}{2}}}+4\,{{\it \_a}}^{3}}}}{d{\it \_a}}-x-{\it \_C2}=0 \right \} \]