Answer:
The rule is x2 -1 (times two minus one)
4 - 1 = 3
4 + 3 = 7
7 - 1 = 6
7 + 6 = 13
13 - 1 = 12
13 + 12 = 25
25 - 1 = 24
25 + 24 = 49
49 - 1 = 48
49 + 48 = 97
