\[ \boxed { {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +ay \left ( x \right ) \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+by \left ( x \right ) =0} \]
Mathematica: cpu = 200.467956 (sec), leaf count = 25 \[ \text {DSolve}\left [a y(x) y'(x)^2+b y(x)+y''(x)=0,y(x),x\right ] \]
Maple: cpu = 0.109 (sec), leaf count = 70 \[ \left \{ \int ^{y \left ( x \right ) }\!{a{\frac {1}{\sqrt {a \left ( { {\rm e}^{-{{\it \_a}}^{2}a}}{\it \_C1}\,a-b \right ) }}}}{d{\it \_a}}-x -{\it \_C2}=0,\int ^{y \left ( x \right ) }\!-{a{\frac {1}{\sqrt {a \left ( {{\rm e}^{-{{\it \_a}}^{2}a}}{\it \_C1}\,a-b \right ) }}}}{d{ \it \_a}}-x-{\it \_C2}=0 \right \} \]