\[ a y(x) y'(x)^2+b y(x)+y''(x)=0 \] ✓ Mathematica : cpu = 0.441204 (sec), leaf count = 96
\[\left \{\left \{y(x)\to \text {InverseFunction}\left [\int _1^{\text {$\#$1}}-\frac {\sqrt {a}}{\sqrt {e^{2 a c_1-a K[1]^2}-b}}dK[1]\& \right ][x+c_2]\right \},\left \{y(x)\to \text {InverseFunction}\left [\int _1^{\text {$\#$1}}\frac {\sqrt {a}}{\sqrt {e^{2 a c_1-a K[2]^2}-b}}dK[2]\& \right ][x+c_2]\right \}\right \}\] ✓ Maple : cpu = 0.765 (sec), leaf count = 70
\[ \left \{ \int ^{y \left ( x \right ) }\!{a{\frac {1}{\sqrt {a \left ( {{\rm e}^{-{{\it \_a}}^{2}a}}{\it \_C1}\,a-b \right ) }}}}{d{\it \_a}}-x-{\it \_C2}=0,\int ^{y \left ( x \right ) }\!-{a{\frac {1}{\sqrt {a \left ( {{\rm e}^{-{{\it \_a}}^{2}a}}{\it \_C1}\,a-b \right ) }}}}{d{\it \_a}}-x-{\it \_C2}=0 \right \} \]