Numerical Sequence Patterns Practice Test

Consider the sequence $$2, 6, 18, 54, 162, \ldots$$ and the sequence $$1, 5, 25, 125, 625, \ldots$$. If the $$n$$th terms of these sequences are added together, what type of sequence is formed?

A sequence begins: $$2, 7, 17, 32, 52, \ldots$$ If this pattern continues, which expression represents the $$n$$th term for $$n \geq 3$$?