A sequence is a set of numbers which follow a certain rule or pattern. Various names to the sequence are given based on the pattern they exhibit. The number \({t_1},{t_2},{t_3}, \ldots  \ldots {t_n}\) are respectively called the first, second, third, …….., \({n^{th}}\) terms of the sequence.

A sequence is called a finite sequence or an infinite sequence according to the number of terms it has. For example

\(1, 3, 5,…….(2n – 1)\)

\(3,{\rm{ }}9,{\rm{ }}27,{\rm{ }} \ldots  \ldots {3^n}\) etc are examples of sequences