\[ a+2 y(x) y''(x)-y'(x)^2=0 \] ✓ Mathematica : cpu = 0.0100427 (sec), leaf count = 31
\[\left \{\left \{y(x)\to \frac {x^2 \left (c_1^2-a\right )}{4 c_2}+c_1 x+c_2\right \}\right \}\]
✓ Maple : cpu = 0.047 (sec), leaf count = 24
\[ \left \{ y \left ( x \right ) ={\frac { \left ( {{\it \_C1}}^{2}-a \right ) {x}^{2}}{4\,{\it \_C2}}}+{\it \_C1}\,x+{\it \_C2} \right \} \]