Domino Effect

A standard set of Double Six dominoes contains 28 pieces (called bones) each displaying
two numbers from 0 (blank) to 6 using dice-like pips. The 28 bones, which are unique,
consist of the following combinations of pips:

Bone # Pips Bone # Pips Bone # Pips Bone # Pips

1 0 | 0 8 1 | 1 15 2 | 3 22 3 | 6
2 0 | 1 9 1 | 2 16 2 | 4 23 4 | 4
3 0 | 2 10 1 | 3 17 2 | 5 24 4 | 5
4 0 | 3 11 1 | 4 18 2 | 6 25 4 | 6
5 0 | 4 12 1 | 5 19 3 | 3 26 5 | 5
6 0 | 5 13 1 | 6 20 3 | 4 27 5 | 6
7 0 | 6 14 2 | 2 21 3 | 5 28 6 | 6