Answer:
evaluate the general expression using n=16
Explanation:
It depends on the sequence.
For arithmetic and geometric sequences, the general term has a well-defined formula for the n-th term. The formula can be evaluated for n=16 to find the 16th term.
Some sequences are defined recursively, so you need to know previous terms before you can find the 16th term. Sometimes those recursive relations can be used to find an explicit relation, letting you use the method of the previous paragraph.
Some sequences have no formula. For example, there is no formula that will give the 16th prime number, or the 16th digit of pi. You must do some research or evaluate some algorithm in order to find the desired term.
Other sequences increase so fast that writing down the terms of the sequence is impossible*. The 16th term can only be indicated using shorthand notations, not actually found.
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* Impossible because there aren't enough resources in the known universe to match the size of the number, or even its number of digits.