How to place 8n objects on a square of size n*n in a form of grid such that no 4 of them forms a rectangle?? Each object occupies exactly 1 cell in the grid. (Given n>=100) . Sides of the rectangle should be parallel to sides of the n by n.

I am not able to figure out any appropriate approach for this problem. I am trying some random object placing but could not achieve the desired result.