What is this equation?

We can’t see all of the third expression, but I can tell you what the first two expressions mean.
The triangle is the Greek letter delta, which means the change. The subscript n+1 and n represent terms in a series of x. n represents the number in the series that the particular term is. So, for example, if I had a series where I started with 1 and added 2 each time, x subscript 3 means the third term in the series of Xs, which would be 5 (1+2+2).
So what those first two expressions are saying is “the change in x is equal to the next term minus the current term.”

Thanks for breaking it down a bit. Perhaps this isn’t anything famous, just an equation that suggests the idea of underlying mathematical principles at work in nature. Could it be some kind of recursive fractal growth model or something? I don’t think I’d know one if I saw one…

It’s a pretty general equation. I wish I could see the rest of it. It is definitely defining a series, which is arguably the most common mathematical element apparent in nature. It’s a really neat idea.

To my eye it looks like a fractal equation – as fractal algorithms can be used to generate forms of that look like natural, such as plant forms like that leaf, because they describe a process, much like plant growth. In fact, that’s the sort of thing “bifurcation” refers to in plants – the process of splitting in two and growing and branching repeatedly. The piece of the equation shown does not describe an entire fractal algorithm that could generate that leaf, but it suggests it is the start of one, even as the start of the leaf there is just the start of the plant…

Nice geeky art. :-)

She’s such a thoughtful artist that it’s bound to mean something, even if it is a mathematical joke. The fractal equation idea makes sense, especially if it looks like one from the fragment in the image. I love the way the sunlight shines through the tiny holes… Thanks for your help. I tried Googling fractal equations for a little bit but didn’t see any that looked like this.

The Xn-1 portion is reminiscent of the beginning of the Fibonacci sequence formula, though the rest of the equation isn’t even similar. I suppose it’s possible that she’s using portions of several of “artistic” and/or “natural” equations that are found in music, nature, etc.

I’ll be interested in seeing if someone identifies it… I love a good inside joke.

fractals sounds about right, it’s probably the equation that explains the way a leaf grows, or the distance between the branches or something