Sequences

First let me explain sequences with an example

Let us consider the following examples:
Assume that there is a generation gap of 30 years, we are asked to find the
number of ancestors, i.e., parents, grandparents, great grandparents, etc. that a person
might have over 300 years.

Here, the total number of generations
The number of person’s ancestors for the first, second, third, …, tenth generations are
2, 4, 8, 16, 32, …, 1024. These numbers form what we call a sequence.

Now let me give more examples and explain types of sequences.