\[ a y(x)-b x^2+x^2 y^{(4)}(x)+2 x y^{(3)}(x)=0 \] ✗ Mathematica : cpu = 300.003 (sec), leaf count = 0 , timed out
$Aborted
✓ Maple : cpu = 0.08 (sec), leaf count = 89
\[\left \{y \left (x \right ) = c_{1} \sqrt {x}\, \BesselJ \left (1, 2 \left (-a \right )^{\frac {1}{4}} \sqrt {x}\right )+c_{2} \sqrt {x}\, \BesselY \left (1, 2 \left (-a \right )^{\frac {1}{4}} \sqrt {x}\right )+c_{3} \sqrt {x}\, \BesselJ \left (1, 2 \sqrt {-\sqrt {-a}}\, \sqrt {x}\right )+c_{4} \sqrt {x}\, \BesselY \left (1, 2 \sqrt {-\sqrt {-a}}\, \sqrt {x}\right )+\frac {b \,x^{2}}{a}\right \}\]