1
Input: 9 → [?] → 18, what is the rule? =
2
Input: 7 → [?] → 14, what is the rule? =
3
Input: 8 → [?] → 13, what is the rule? =
4
Input: 6 → [?] → 16, what is the rule? =
5
Input: 8 → [?] → 5, what is the rule? =
6
Input: 6 → [?] → 18, what is the rule? =
8
Input: 10 → [?] → 50, what is the rule? =