(1,8,15);(2,7,12);(3,4,5);(6,10,14);(9,11,13).
The above line represents grouping of the first 15 integers into disjoint subsets of 3 elements, each triplet being an ascending arithmetic progression - each triplet with unique difference.
List all possible groupings into 5 triplets - each grouping with another set of 5 distinct differences.
Order the triplets by the value of the 1st element, like in the example shown.