\[ \boxed { 4\,{x}^{2}{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +4\,x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +f \left ( x \right ) y \left ( x \right ) =0} \]
Mathematica: cpu = 0.268034 (sec), leaf count = 28 \[ \text {DSolve}\left [f(x) y(x)+4 x^2 y''(x)+4 x y'(x)=0,y(x),x\right ] \]
Maple: cpu = 0.0 (sec), leaf count = 33 \[ \left \{ y \left ( x \right ) ={\it DESol} \left ( \left \{ {\frac {f \left ( x \right ) {\it \_Y} \left ( x \right ) }{4\,{x}^{2}}}+{\frac {{ \frac {\rm d}{{\rm d}x}}{\it \_Y} \left ( x \right ) }{x}}+{\frac { {\rm d}^{2}}{{\rm d}{x}^{2}}}{\it \_Y} \left ( x \right ) \right \} , \left \{ {\it \_Y} \left ( x \right ) \right \} \right ) \right \} \]