1
Input: 4 → [?] → 3, what is the rule? =
2
Input: 4 → [+4 ×2] → ? =
3
Input: 5 → [?] → 10, what is the rule? =
4
Input: 10 → [?] → 9, what is the rule? =
5
Input: 9 → [?] → 18, what is the rule? =
6
Input: 2 → [?] → 12, what is the rule? =
8
Input: 4 → [?] → 14, what is the rule? =