\[ y'(x)=\frac {2 a}{x \left (-8 a^2+2 a x y(x)^2-x y(x)\right )} \] ✓ Mathematica : cpu = 0.294872 (sec), leaf count = 39
\[\text {Solve}\left [\frac {y(x)^2 e^{-4 a y(x)}}{8 a}-\frac {e^{-4 a y(x)}}{2 x}=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.475 (sec), leaf count = 28
\[c_{1}+\frac {\left (-x y \relax (x )^{2}+4 a \right ) {\mathrm e}^{-4 a y \relax (x )}}{x} = 0\]