\[ y'(x)=\frac {\sin \left (\frac {y(x)}{x}\right ) \csc \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{2 x}\right ) \left (2 x^3 \sin \left (\frac {y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )+y(x)\right )}{2 x} \] ✓ Mathematica : cpu = 0.109158 (sec), leaf count = 23
DSolve[Derivative[1][y][x] == (Csc[y[x]/(2*x)]*Sec[y[x]/(2*x)]*Sin[y[x]/x]*(2*x^3*Cos[y[x]/(2*x)]*Sin[y[x]/(2*x)] + y[x]))/(2*x),y[x],x]
\[\left \{\left \{y(x)\to 2 x \cot ^{-1}\left (e^{-\frac {x^2}{2}-c_1}\right )\right \}\right \}\] ✓ Maple : cpu = 0.091 (sec), leaf count = 64
dsolve(diff(y(x),x) = 1/2*sin(y(x)/x)*(y(x)+2*x^3*cos(1/2*y(x)/x)*sin(1/2*y(x)/x))/sin(1/2*y(x)/x)/x/cos(1/2*y(x)/x),y(x))
\[y \left (x \right ) = \arctan \left (\frac {2 \,{\mathrm e}^{\frac {x^{2}}{2}} c_{1}}{{\mathrm e}^{x^{2}} c_{1}^{2}+1}, \frac {-{\mathrm e}^{x^{2}} c_{1}^{2}+1}{{\mathrm e}^{x^{2}} c_{1}^{2}+1}\right ) x\]