\[ \boxed { 4\,{x}^{2}{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) -{x}^{4} \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+4\,y \left ( x \right ) =0} \]
Mathematica: cpu = 10.873881 (sec), leaf count = 31 \[ \text {DSolve}\left [x^4 \left (-y'(x)^2\right )+4 x^2 y''(x)+4 y(x)=0,y(x),x\right ] \]
Maple: cpu = 1.092 (sec), leaf count = 103 \[ \left \{ y \left ( x \right ) ={\it ODESolStruc} \left ( {\frac {{\it \_a }}{ \left ( {{\rm e}^{\int \!{\it \_b} \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}}} \right ) ^{2}}},[ \left \{ {\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) = \left ( -{{\it \_a}}^{2}+7\,{\it \_a} \right ) \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{3}+ \left ( {\it \_a}-5 \right ) \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}-{\frac {{\it \_b} \left ( { \it \_a} \right ) }{4}} \right \} , \left \{ {\it \_a}={x}^{2}y \left ( x \right ) ,{\it \_b} \left ( {\it \_a} \right ) ={\frac {1}{{x}^{2} \left ( x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +2\,y \left ( x \right ) \right ) }} \right \} , \left \{ x={{\rm e}^{\int \!{\it \_b} \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}}},y \left ( x \right ) ={\frac {{\it \_a}}{ \left ( {{\rm e}^{\int \!{\it \_b} \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}}} \right ) ^{2} }} \right \} ] \right ) \right \} \]