\[ 6 a^2 y(x)+5 a y'(x)+y''(x)-6 y(x)^2=0 \] ✓ Mathematica : cpu = 1.18197 (sec), leaf count = 35
\[\left \{\left \{y(x)\to a^2 c_1{}^2 e^{-2 a x} \wp \left (e^{-a x} c_1+c_2;0,-1\right )\right \}\right \}\] ✓ Maple : cpu = 0.844 (sec), leaf count = 27
\[y \relax (x ) = \WeierstrassP \left (-\frac {{\mathrm e}^{-a x}}{a}+c_{1}, 0, c_{2}\right ) {\mathrm e}^{-2 a x}\]