Explain Sequences

Introduction of sequences, A sequence is a function from the group of natural numbers to the group of real numbers . The sequence  is represented by the letter a, where the image of 'n' belongs to the integer number 'N' under the sequence 'a' is a(n) = an. Since the domain for every sequence is the set of natural numbers, like 1, 2, 3, … n under the sequence.Here a_1, a₂, a₃ … an form the sequence.