Triads-Up

1 – 2 – 3 – 4 - 2 – 3 – 4 – 5 - 3 – 4 – 5 – 6 - 4 – 5 – 6 – 7 -
5 – 6 – 7 – 8 - 6 – 7 – 8 – 9 - 7 – 8 – 9 – 10 - 9 – 10– 11 – 12