Yes, you are on the right track. That is absolutely corect. Yes, I wish there was a whiteboard. I will see if I can upload a diagram from Paint...
Here is the diagram...please forgive my unsteady hand. (Smile)
I have looked at the diagram you've mentioned. My diagram begins with one square as fig. 1, then fig. 2 has a base of three squares with 1 square on top; fig. 3 has a base of five squares with the 2nd layer having three squares and the third layer having 1 square; figure 4. has a base of 7...