nth term
A formula in terms of n that gives any term of a sequence.
Definition
For an arithmetic sequence with first term a and common difference d, the nth term is a + (n − 1)d. For a geometric sequence with first term a and common ratio r, the nth term is ar^(n − 1).
Example
Sequence 5, 9, 13, 17. First term 5, common difference 4. nth term = 5 + (n − 1) × 4 = 4n + 1.
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