An arithmetic sequence with at least four terms is 1, 5, 9, 13, 17, 21....
where,
a = first term = 1
n = number of terms
d = common difference = 5 - 1 = 4
From the example given, the first term is 1, and the common difference is 4
Read related link on:
https://brainly.com/question/24456969