1
Input: 7 → [?] → 22, what is the rule? =
2
Input: 1 → [?] → 0, what is the rule? =
3
Input: 3 → [?] → 8, what is the rule? =
5
Input: 9 → [?] → 18, what is the rule? =
6
Input: 9 → [?] → 25, what is the rule? =
7
Input: 8 → [?] → 19, what is the rule? =