Question

Find the formula for the general term a: {5,1,5,1,5,1}

Answer 1

3+2(-1)^(n+1)

Answer 2

You most certainly could do that. Depending on what your teacher wants, you could also write it in the following valid manner.\[\Large a_n = \left\{\begin{array}{ll}5 & \text{if $n$ is odd} \\ 1 & \text{if $n$ is even}\end{array}\right.\]