The formula of the sequence shows f(n+1) = 1.5f(n)
Recursive equation should need a sentinel value. In the question given, the sentinel value is not presented.
If we assign a sentinel value of f(1) = 2.
The next term f(2) will be:
f(2) = 1.5 f(1)
f(2) = 1.5 * 2
f(2) = 3.