import rhinoscriptsyntax as rs 
allobjs=rs.AllObjects()
rs.DeleteObjects(allobjs)

bsize=10
dist=1
offs=bsize+dist
num=10

#create a box
corners = [(0,0,0), (10,0,0), (10,10,0), (0,10,0), (0,0,10), (10,0,10), (10,10,10), (0,10,10)]

for i in range(num):
    for j in range(num):
        if ((i+j)%5) and ((i-j)%3):
            box=rs.AddBox(corners)
            rs.MoveObject(box,(i*offs,j*offs,0))