
A Fractal which is the 3D analog of the Sierpinski Carpet. Let be the number
of filled boxes, the length of a side of a hole, and the fractional Volume after the th
iteration.
(1)  
(2)  
(3) 
(4) 
J. Mosely is leading an effort to construct a large Menger sponge out of old business cards.
See also Sierpinski Carpet, Tetrix
References
Dickau, R. M. ``Menger (Sierpinski) Sponge.'' http://forum.swarthmore.edu/advanced/robertd/sponge.html.
Mosely, J. ``Menger's Sponge (Depth 3).'' http://world.std.com/~j9/sponge/.