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

${a}_{n} = 2 n + 1$
$3 , 5 , 7 , 9 , \ldots$ is the sequence of odd positive integers except the integer $1$.
${a}_{n} = \left(2 n - 1\right) \forall n \in \mathbb{N}$ is the set of all odd natural numbers.
Hence, ${a}_{n} = \left(2 n + 1\right) : n \ge 1$ will generate this sequence and is therefore the general ${n}^{t h}$ term