Question

How do you write a formula for an, the n th term for the given sequence: 3, 5, 7, 9, …?

Answer 1

`a_n=2n+1`

Explanation:

`3,5,7,9,...` is the sequence of odd positive integers except the integer `1`.

`a_n = (2n-1) forall n in NN` is the set of all odd natural numbers.

Hence, `a_n = (2n+1): n>=1` will generate this sequence and is therefore the general `n^(th)` term