\[ -\left (a x^2+12 a+4\right ) \cos (x)+x^2 y''(x)-2 x y'(x)-4 y(x)-x \sin (x)=0 \] ✓ Mathematica : cpu = 0.172783 (sec), leaf count = 38
\[\left \{\left \{y(x)\to \frac {-2 a \sin (x)-a x \cos (x)-\sin (x)}{x}+c_2 x^4+\frac {c_1}{x}\right \}\right \}\]
✓ Maple : cpu = 0.053 (sec), leaf count = 33
\[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}}{x}}+{\it \_C2}\,{x}^{4}-{\frac {ax\cos \left ( x \right ) +2\,\sin \left ( x \right ) a+\sin \left ( x \right ) }{x}} \right \} \]