A sequence is a set of numbers that are grouped in a particular order. The number of elements in the stream can be infinite, and these sequences are called streams. A subsequence is a sequence that's created from another sequence. The relative positions of the elements in a subsequence will remain the same after deleting some of the elements in a sequence.
In the following sections, we will take a look at different sequences such as the Farey sequence, Fibonacci sequence, look-and-say, and Thue–Morse.