For any grid, x by x, figure out a formula for the greatest number of points that can be put on the inside of the grid such that no three points are colinear.

(In reply to re(2): Theoretical limits reachable? - McWorter by Avin)

Das ist sehr richtig!  I caught the error too, but only after I submitted the comment.  Here's another try, including one for 7x7.

 

7x7

oooxoxo

ooxoxoo

xooooox

oxoooxo

xooooox

ooxoxoo

oxoxooo

 

8x8

oooxooox

ooxoooxo

xoooxooo

oxoooxoo

xoooxooo

oxoooxoo

oooxooox

ooxoooxo

 

It looks like the real challenge of this problem is the construction of 2x grid points with no three collinear points.

Posted by McWorter on 2005-05-20 02:50:13