A 2x3x3 block with I_2 containing no other subboxes.

  1 1 2   5 6 6
  3 x 2   5 x 7
  3 4 4   8 8 7

A 2x4x4 block with I_2 containing no other subboxes.

  x 1 1 2   x 6 1 1
  6 6 x 2   5 6 x 2
  5 x 3 3   5 x 3 2
  5 4 4 x   4 4 3 x


A 3x5x5 block with I_3 containing no other subboxes.

  x 1 1 1 u    x 7 v v v    x 1 1 1 u
  2 2 2 x u    6 7 8 x 0    2 2 2 x u
  u 3 3 3 u    6 7 8 9 0    u 3 3 3 u
  u x 4 4 4    6 x 8 9 0    u x 4 4 4
  u 5 5 5 x    v v v 9 x    u 5 5 5 x