Chebyshev distance is an interesting concept stating the relative distance in terms of matrix. For example, if we consider center of a 2-D matrix as starting point

2 2 2 2 2
2 1 1 1 2
2 1 X 1 2
2 1 1 1 2
2 2 2 2 2

Where X is starting point.

On a 2-D plane this distance is max(mod(x2-x1),mod(y2-y1))
or in a 2-D matrix, considering above example,
max(mod( rowindex – maxnum), mod(colindex – maxnum))
maxnum being 2 in above example

A small code to calculate above

public ArrayList<ArrayList> chebyshev(int A) {
ArrayList<ArrayList> arr =new ArrayList<>();
// maxnum = A
//max(mod( rowindex – maxnum), mod(colindex-maxnum))
int size=A*2+1;
int maxnum=A;
for(int i=0;i< size;i++)

{
ArrayList arrin=new ArrayList<>();
for(int j=0;j< size;j++)

{
int rownum=i-maxnum;
//mod
if(rownum<0)rownum*=-1;
int colnum=j-maxnum;
if(colnum<0)colnum*=-1;
//find max
int num=(colnum<rownum)?rownum:colnum;
arrin.add(num);
}
arr.add(arrin);
}
return arr;
}