The general term is 
(a sub n; n is a subscript)
The first term is a1
The second term is a2
The third term is a3
and so on...
The first term starts at n = 1. We replace the n in with 1 to get 
. A similar thing happens with n = 2 and onward
The domain is therefore the set {1, 2, 3, 4, 5, ...} which is the set of...
* Counting numbers
* Positive Whole numbers
* Natural numbers
Those are three ways to express the same set
We can also say
where n is an integer or whole number
A similar inequality would be
which is effectively the same as idea as the last inequality (n is also an integer or whole number).
The first term is a1
The second term is a2
The third term is a3
and so on...
The first term starts at n = 1. We replace the n in
The domain is therefore the set {1, 2, 3, 4, 5, ...} which is the set of...
* Counting numbers
* Positive Whole numbers
* Natural numbers
Those are three ways to express the same set
We can also say
A similar inequality would be