\[ y^{(3)}(x)-\lambda y(x)=0 \] ✓ Mathematica : cpu = 0.0414995 (sec), leaf count = 53
\[\left \{\left \{y(x)\to c_1 e^{(-1)^{2/3} \sqrt [3]{\lambda } x}+c_2 e^{-\sqrt [3]{-1} \sqrt [3]{\lambda } x}+c_3 e^{\sqrt [3]{\lambda } x}\right \}\right \}\] ✓ Maple : cpu = 0.022 (sec), leaf count = 47
\[\left \{y \left (x \right ) = c_{1} {\mathrm e}^{-\frac {\left (1+i \sqrt {3}\right ) \lambda ^{\frac {1}{3}} x}{2}}+c_{2} {\mathrm e}^{\frac {\left (i \sqrt {3}-1\right ) \lambda ^{\frac {1}{3}} x}{2}}+c_{3} {\mathrm e}^{\lambda ^{\frac {1}{3}} x}\right \}\]