Find the law from the sequence If the first cycle is 1, the second cycle is 4, the third cycle is 7, and so on, what is the number of N cycles? (it can be expressed by an algebraic expression containing n)

Find the law from the sequence If the first cycle is 1, the second cycle is 4, the third cycle is 7, and so on, what is the number of N cycles? (it can be expressed by an algebraic expression containing n)

an=1+3(n-1) = 3n-2