\[
\boxed{
ny \left( x \right) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) - \left( n-1 \right)  \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}=0}
\]