I need a matrix of 256 x 256 unsigned short values... The matrix can be implemented as a list of lists or a tuple... So for example: [[1][2][3], [4][5][6], [7][8][9]] or ((1,2,3),(4,5,6), (7,8,9)) This is what I have so far but its not working... a = [][] for i in range(0,256): for j in range(0,256): a[i][j] = i**2