Posted by **Carter** on Thursday, April 5, 2007 at 11:01pm.

What are the following symbols used in math sequences: a sub i, n, N?

a_{i} is the ith element of the sequence

n is the value of i in the term you are refering to. For instance, 3,4,5,6 a_{3} is 5. That term corresponds to n=3

N is the number of terms in the sequence.