\[
\boxed{
{x}^{2}{\it d4y} \left( x \right) -2\, \left( {\nu}^{2}{x}^{2}+6 \right) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) +{\nu}^{2} \left( {\nu}^{2}{x}^{2}+4 \right) y \left( x \right) =0}
\]