and surely the n=1 term must be 1, not 2 In general i think we are filling an n^2 X n^2 grid with numbers from 1 to n such that in each of the n^2 nXn subboxes we get all of 1..n; and in each row we get all of 1..n, etc. For n=1 there is a unique solution, namely: [1] NJAS