There are seven situations:
1. Each element is an equivalence class (1, 1, 1, 1), with 1 species.
2, there are two equivalence classes, and each element of the rest has one (2, 1, 1, 1) and 10 (permutation number calculation).
3, two equivalence classes with two elements, leaving one equivalence class with one element (2,2, 1), 15.
4, a three-element equivalence class, the rest are all one-element equivalence classes (3, 1, 1), and there are 10 kinds.
5, one with three elements and one with two elements, (3,2), 10 species.
6. One element with four elements, (4, 1), 5 kinds.
7. An equivalent class (5) in the five elements, 1 species.