What is sequence

Sequence

              A set of numbers arranged in a definite order according to some definite rule is called a sequence.
or
A sequence is a function whose domain is the set N of natural numbers.
It is customary to denote a sequence by a letter 'a' and the image a(n) or t(n), n Î N under 'a' by a_n or t_n.

Examples:

1, 3, 5, 7…..... (adding 2 to every term)
1, 4, 16, 64 … (Multiplying by 4 every term)
20, 17, 14 … . (add -3 to every term)
The different numbers in a sequence are called terms of sequence.
The subscripts denote the position of the term.
In the second example, 4 is the second term, and 14 is the third term in the third example.
The nth term of a sequence is called the general term of the sequence and is usually denoted by a_n or t_n.


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