Sequences and series

Wikimedia Commons has media related to Sequence.

In mathematics, a sequence is a list of objects (or events) which have been ordered in a sequential fashion; such that each member either comes before, or after, every other member. More formally, a sequence is a function with a domain equal to the set of positive integers.

A series is a sum of a sequence of terms. That is, a series is a list of numbers with addition operations between them.