I should have said Table, not chart
It had multiple rows:
The first one: 4 grandparents, then 4 identified or something similar
The second row: 8 grt grandparents, then 6 of 8 identified
The third row: 16 2 X grt grandparents,
etc, etc to about 9 or 10 generations
Someone posted an example on a Weekend chat a while ago, I have looked through recent weekend chats and haven't found it yet.