Problem 45421. Abelian Sandpile - 02

Generate a matrix like Abelian Sandpile where the four corner element is n.

For example, n=4

    [4     3     2     1     0     1     2     3     4
     3     3     2     1     0     1     2     3     3
     2     2     2     1     0     1     2     2     2
     1     1     1     1     0     1     1     1     1
     0     0     0     0     0     0     0     0     0
     1     1     1     1     0     1     1     1     1
     2     2     2     1     0     1     2     2     2
     3     3     2     1     0     1     2     3     3
     4     3     2     1     0     1     2     3     4]