ELI5: Explain Like I'm 5

Arithmetico-geometric sequence

Ok, let's play a game!

Imagine you have a cake, but instead of just eating it all at once, you want to eat it little by little every day. And every day, you want to eat a little more cake than the day before. This is called an arithmetico-geometric sequence.

Let's break it down into two parts: arithmetico and geometric.

Arithmetico means that you're adding a certain number every time. So in our cake example, let's say you want to add one extra bite of cake every day. That means on day one, you can have one bite, on day two, you can have two bites, on day three, you can have three bites, and so on.

Geometric means that you're multiplying by a certain factor every time. So let's say you also want to make each bite of cake a little bigger every day. Maybe on day one, you only take a tiny nibble, but on day two, you take a slightly bigger bite, and on day three, an even bigger bite than that.

Now let's combine these two ideas. You're adding one extra bite of cake every day, AND you're making each bite a little bigger than the day before. This is what we call an arithmetico-geometric sequence!

So at the end of a week, you'll have eaten more cake than you did on day one, but it won't be a crazy amount because you're only adding one bite at a time. But because each bite is a little bigger than the one before, you'll still feel pretty satisfied.

And that's how you can eat cake every day and still be healthy! ...Ok, maybe not *that* healthy. But it's a fun way to think about arithmetico-geometric sequences.