Concept history

Concept created

Let $X$ be a [[Set|set]]. A sequence in $X$ is a [[Function|function]] $a:\N \rightarrow X$.

##### Remarks
- The value $a(n)$ is written $a_{n}$ and called the $n$-th term, while the sequence itself is usually denoted $(a_{n})_{n\in \N}$ or simply $(a_{n})$.