Question

What is the term to term rule: 21, 17, 13, 9, 5, 1

Answer 1

An = A(n-1) - 4

Explanation:

21 - 17 = 4

17 - 13 = 4

13 - 9 = 4

9 - 5 = 4

5 - 1 = 4

ratio = 4

An = A(n-1) - 4