We can demonstrate through circle connecting dots. Like 1 dot is 1 region, connect 2 dots that form 2 regions, connect 3 dots that form 4 regions, connect 4 dots that form 8 regions, connect 5 dots and we get 16 regions, connect 6 dots and we get 31 regions and so on. We explored this back in college days.
Exactly the example I was thinking of.
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