# General Information on Sequences & Series

Making a **pattern** can be quite easy, anything that repeats could be a pattern, such as 565656, or cat dog cat dog cat dog. To find a pattern you often need 2 full repeats of the pattern.

**Sequences** are ordered sets of items, which makes it possible to easily determine the next item. This term is often reserved for numbers, but it very similar to a pattern. To determine a sequence you often need at least 3 terms of the sequence or the definition.

For example, we can have a sequence starting with 2, 4, 6, and we add all 3 numbers to get the next, so the next number would be 12, i.e. 2, 4, 6, 12, 22, 40, …

**Series** are often confused with a sequences, but mathematically it is the sum of the sequence.