There is another program arranged in a similar circular shape that calculated pi experimentally using it's own source code as the circle to test.
The neat thing is that the program itself is ASCII art, and downscaling the program source code will generate valid programs for 3 iterations![2]
[1] http://www.ioccc.org/2011/akari/akari.c [2] http://www.ioccc.org/2011/akari/hint.html