1
Input: 3 → [?] → 13, what is the rule? =
2
Input: 7 → [?] → 14, what is the rule? =
4
Input: 7 → [?] → 19, what is the rule? =
5
Input: 1 → [?] → 3, what is the rule? =
6
Input: 5 → [?] → 4, what is the rule? =
7
Input: 7 → [?] → 12, what is the rule? =
8
Input: 3 → [?] → 0, what is the rule? =