Once again, Paul Laseau and James Tice, authors of “Frank Lloyd Wright, Between Principle and Form” reveal an element of Frank Lloyd Wright’s fractal intuition. A fractal pattern called an “Apollonian Net” or “Apollonian Gasket” is composed of a triplet of circles, each of which is tangent to the others. A complete description can be found at Wolfram MathWorld.
This is not as common as other fractals, but it still represents self-similarity of scale. The three circles do not necessarily have to be within another circle, as the MathWorld entry shows.

The image below is from Paul Laseau’s and James Tice’s book, p. 37. The left column shows a clear fractal pattern.
