1
Input: 3 → [?] → 9, what is the rule? =
2
Input: 4 → [?] → 3, what is the rule? =
3
Input: 7 → [?] → 35, what is the rule? =
4
Input: 9 → [?] → 27, what is the rule? =
6
Input: 7 → [?] → 12, what is the rule? =
8
Input: 3 → [?] → 6, what is the rule? =