In a $2n$-dimensional matrix $a_{ij}=\begin{cases}1\text{ if }i\le n\text{ and }j\ge n+1\text{ or }i\ge n+1\text{ and }j\le n\\0\text{ otherwise}\end{cases}$
In a $2n$-dimensional matrix $a_{ij}=\begin{cases}1\text{ if }i\le n\text{ and }j\ge n+1\text{ or }i\ge n+1\text{ and }j\le n\\0\text{ otherwise}\end{cases}$