\[ -a e^x y(x)^2+y'(x)-y(x)^3=0 \] ✓ Mathematica : cpu = 0.933557 (sec), leaf count = 78
DSolve[-(a*E^x*y[x]^2) - y[x]^3 + Derivative[1][y][x] == 0,y[x],x]
\[\text {Solve}\left [-i a e^x=\frac {2 e^{\frac {1}{2} \left (-i a e^x-\frac {i}{y(x)}\right )^2}}{\sqrt {2 \pi } \text {erfi}\left (\frac {-i a e^x-\frac {i}{y(x)}}{\sqrt {2}}\right )+2 c_1},y(x)\right ]\] ✓ Maple : cpu = 0.09 (sec), leaf count = 50
dsolve(diff(y(x),x)-y(x)^3-a*exp(x)*y(x)^2 = 0,y(x))
\[c_{1}+\frac {{\mathrm e}^{-\frac {\left ({\mathrm e}^{x} a +\frac {1}{y \left (x \right )}\right )^{2}}{2}} {\mathrm e}^{-x}}{a}+\frac {\erf \left (\frac {\left ({\mathrm e}^{x} a +\frac {1}{y \left (x \right )}\right ) \sqrt {2}}{2}\right ) \sqrt {2}\, \sqrt {\pi }}{2} = 0\]