\[ 4 x y''(x)-(a+x) y(x)=0 \] ✓ Mathematica : cpu = 0.100412 (sec), leaf count = 44
\[\left \{\left \{y(x)\to \frac {1}{4} e^{-x/2} x \left (c_2 \, _1F_1\left (\frac {a}{4}+1;2;x\right )+c_1 U\left (\frac {a}{4}+1,2,x\right )\right )\right \}\right \}\]
✓ Maple : cpu = 0.052 (sec), leaf count = 21
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,{{\sl M}_{-{\frac {a}{4}},\,{\frac {1}{2}}}\left (x\right )}+{\it \_C2}\,{{\sl W}_{-{\frac {a}{4}},\,{\frac {1}{2}}}\left (x\right )} \right \} \]