\[ y(x) \left (a e^{2 x}+b e^x+c\right )+y''(x)=0 \] ✓ Mathematica : cpu = 0.727741 (sec), leaf count = 136
\[\left \{\left \{y(x)\to e^{-i \sqrt {a} e^x} \left (e^x\right )^{i \sqrt {c}} \left (c_1 U\left (\frac {i b}{2 \sqrt {a}}+i \sqrt {c}+\frac {1}{2},2 i \sqrt {c}+1,2 i \sqrt {a} e^x\right )+c_2 L_{-\frac {i b}{2 \sqrt {a}}-i \sqrt {c}-\frac {1}{2}}^{2 i \sqrt {c}}\left (2 i \sqrt {a} e^x\right )\right )\right \}\right \}\]
✓ Maple : cpu = 0.396 (sec), leaf count = 58
\[ \left \{ y \left ( x \right ) ={{\rm e}^{-{\frac {x}{2}}}} \left ( {{\sl M}_{{-{\frac {i}{2}}b{\frac {1}{\sqrt {a}}}},\,i\sqrt {c}}\left (2\,i\sqrt {a}{{\rm e}^{x}}\right )}{\it \_C1}+{{\sl W}_{{-{\frac {i}{2}}b{\frac {1}{\sqrt {a}}}},\,i\sqrt {c}}\left (2\,i\sqrt {a}{{\rm e}^{x}}\right )}{\it \_C2} \right ) \right \} \]