Produce a graphical representation of a Sierpinski triangle of order N in any orientation.

An example of Sierpinski's triangle (order = 8) looks like this: 




include c:\cxpl\codes;          \intrinsic 'code' declarations
def Order=7, Size=1<<Order;
int X, Y;
[SetVid($13);                   \set 320x200 graphics video mode
for Y:= 0 to Size-1 do
    for X:= 0 to Size-1 do
        if (X&Y)=0 then Point(X, Y, 4\red\);
X:= ChIn(1);                    \wait for keystroke
SetVid(3);                      \restore normal text display
]