Binary Tree | Why Child Nodes are (2*Parent Node) and (2*Parent Node +1)?

Описание: We all know that serial number of a child node in a Binary Tree is 2 times serial number of parent node. Ever thought why it is always the case?
Here I will explain by simple mathematics, that child node of a node has to be 2*n and 2*n+1 where n is the serial number of the parent node.
This is only true for a Binary Tree we can also find for k-ary trees, by using the same logic as explained in the video.
It is my first youtube video. Do support me guys. I have a small list of such videos which I want to put it in public if this goes well.