\[ a y'(x)+b y(x)+y'(x)^2=0 \] ✓ Mathematica : cpu = 0.227776 (sec), leaf count = 110
\[\left \{\left \{y(x)\to \text {InverseFunction}\left [-\frac {\sqrt {a^2-4 \text {$\#$1} b}+a \log \left (a-\sqrt {a^2-4 \text {$\#$1} b}\right )}{2 b}\& \right ]\left [\frac {x}{2}+c_1\right ]\right \},\left \{y(x)\to \text {InverseFunction}\left [-\frac {\sqrt {a^2-4 \text {$\#$1} b}-a \log \left (\sqrt {a^2-4 \text {$\#$1} b}+a\right )}{2 b}\& \right ]\left [-\frac {x}{2}+c_1\right ]\right \}\right \}\] ✓ Maple : cpu = 0.734 (sec), leaf count = 279
\[y \relax (x ) = -\frac {a^{2} \left (\LambertW \left (-\frac {2 \sqrt {-b}\, {\mathrm e}^{\frac {c_{1} b}{a}} {\mathrm e}^{-\frac {b x}{a}} {\mathrm e}^{-1}}{a}\right )+2\right ) \LambertW \left (-\frac {2 \sqrt {-b}\, {\mathrm e}^{\frac {c_{1} b}{a}} {\mathrm e}^{-\frac {b x}{a}} {\mathrm e}^{-1}}{a}\right )}{4 b}\]