$(1\mathrm{.}25$ points$)$ Determine the output y$($n$),1$ n $15$ for the following difference equation using aMATLAB function which accepts n as the input.y$($n$)+$ y$($n $1)+$ y$($n $2)=$ u$($n $1)$; y$(0)=1,$ y$(1)=6$ where the input u$($n$)=()$n$,$ n $0.($Be careful about the indices, because MATLAB starts a vector with the index of $1.)$