Let's call the rolls roll A, B, and C
We can just multiply all combinations by 3 and get the answer because AAAABC would just be BBBBAC and CCCCBA following the same pattern
ABCABC
AAAABC * 3 = 3
AAABCC * 3 = 9
AAABBC
AABBCC *3 = 18
AABCCC
AABBBC
ABBBCC * 3 = 30
ABBCCC
ABCCCC
ACBBBB
Curiously enough to went 3 + 6 + 9 + 12. Answer is 30