\[ y'(x)=\frac {-2 a x^2-x^3-4 x y(x)-4 x+8}{4 a x+2 x^2+8 y(x)+8} \] ✓ Mathematica : cpu = 0.0451379 (sec), leaf count = 45
\[\left \{\left \{y(x)\to \frac {1}{4} \left (-2 a x-x^2-4\right )-\frac {2 \left (1+W\left (-e^{-\frac {a^2 x}{4}-1+c_1}\right )\right )}{a}\right \}\right \}\] ✓ Maple : cpu = 0.165 (sec), leaf count = 51
\[\left \{y \left (x \right ) = \frac {-2 a^{2} x -a \,x^{2}-4 a -8 \LambertW \left (-\frac {{\mathrm e}^{-1} {\mathrm e}^{-\frac {a}{2}} {\mathrm e}^{\frac {c_{1} a^{2}}{4}} {\mathrm e}^{-\frac {a^{2} x}{4}}}{2}\right )-8}{4 a}\right \}\]