The Sierpiski Triangle is obtained as the residual set remaining when one begins with a triangle and applies the operation of dividing it into four equal triangles and omitting the interior of the center one, then repeats this operation on each of the surviving 3 triangles, then repeats again on the surviving 9 triangles, and so on . See [36, Example 2.7].
The Sierpiski Triangle is
homeomorphic to the unique nonempty compact set K of the
complex plane that satisfies