We have all seen lists of numbers. For example, we’ve all worked with a list of positive even integers presented in increasing order, \((2, 4, 6, \ldots , 2 n , \ldots )\) , where \(n = 1, 2, 3, \ldots .\) The positive odd numbers \((1, 3, 5, \ldots , 2n - 1, \ldots )\) can also be presented in such a list, where \(n = 1, 2, 3, \ldots .\) What we are interested in here is a precise definition of “infinite list.” In fact, this “list” is just a sequence and a sequence is just a function on the natural numbers. So, putting everything you’ve learned together, you’ll know a lot more about sequences than you might imagine.