In the sequence 9, 27, 81, 243, 729, ..., what is the second set of finite differences?

Given the sequence 4, 14, 30, 52, 80, ..., what is the second set of finite differences?

In the sequence 12, 22, 32, 42, 52, ..., what is the first set of finite differences?

Consider the sequence 1, 3, 7, 15, 31, ... What is the order of the polynomial for this sequence?

In the sequence 1, 8, 27, 64, 125, ..., what is the third set of finite differences? 

Given the sequence 2, 6, 18, 54, 162, ..., what is the common ratio? 

In the sequence 3, 7, 11, 15, 19, ..., what is the common difference? 

In the sequence 18, 12, 6, 0, -6, ..., what is the common difference?

In the sequence 16, 8, 4, 2, 1, ..., what is the common ratio?

Given the sequence 1, 4, 9, 16, 25, ..., what are the second set of finite differences?