\[ y'(x)=\frac {2 a}{x \left (-8 a^2+2 a x y(x)^2-x y(x)\right )} \] ✓ Mathematica : cpu = 0.34566 (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 = 0.356 (sec), leaf count = 28
\[\left \{c_{1}+\frac {\left (-x y \left (x \right )^{2}+4 a \right ) {\mathrm e}^{-4 a y \left (x \right )}}{x} = 0\right \}\]