\[
\boxed{
{x}^{2}{\frac {{\rm d}^{3}}{{\rm d}{x}^{3}}}y \left( x \right) -3\, \left( x-m \right) x{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) + \left( 2\,{x}^{2}+4\, \left( n-m \right) x+m \left( 2\,m-1 \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) -2\,n \left( 2\,x-2\,m+1 \right) y \left( x \right) =0}
\]