The th-order Sierpiński tetrahedron graph is the connectivity graph of black triangles in the th iteration of the tetrix fractal. The first three iterations are shown above. It is the three-dimensional analog of the Sierpiński gasket graph and can be further generalized to higher dimensions (D. Knuth, pers. comm., May 1, 2022).

The -Sierpiński tetrahedron graph has vertices and edges.