\[ \boxed { \left ( 2\,x+1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -4\,{{\rm e}^{-y \left ( x \right ) }}+2=0} \]
Mathematica: cpu = 0.018002 (sec), leaf count = 21 \[ \left \{\left \{y(x)\to \log \left (2-\frac {e^{c_1}}{2 x+1}\right )\right \}\right \} \]
Maple: cpu = 0.141 (sec), leaf count = 34 \[ \left \{ y \left ( x \right ) =-\ln \left ( {\frac {2\,x+1}{-1+4\,x{ {\rm e}^{2\,{\it \_C1}}}+2\,{{\rm e}^{2\,{\it \_C1}}}}} \right ) -2\,{ \it \_C1} \right \} \]