In cases such as this one, it is often a lot easier to compute the combinations first, then convert them into permutations as follows:
(22222, 22223, 22224, 22227, 22228, 22233, 22234, 22237, 22238, 22247, 22248, 22278, 22333, 22334, 22337, 22338, 22347, 22348, 22378, 22478, 23333, 23334, 23337, 23338, 23347, 23348, 23378, 23478, 33333, 33334, 33337, 33338, 33347, 33348, 33378, 33478) >>Total = 36 combinations.
These 36 combinations break down as follows:
2 Ccombinations x 1 Permutation each == 2P
8 C x 5P ==40P
2 C x 10P ==20P
12 C x 20P ==240P
3 C x 30P ==90P
8 C x 60P ==480P
1 C x 120P==120P
Total combinations == 36
Total permutations == 992