Establish a recursion relation

Question

Response to the following problem:

1.Establish a recursion relation for calculating the elements a_ij of Σ^{- 1}:

a_ij = {2i²     if i = j < n,
       {n²      if i = j = n,
       {-ij       if |i - j| = 1,
       {0       otherwisw

2. Show that the bias due to the replacement of μ by x¯ n is of the order of a X²_n  term, which can thus be corrected directly in dn.