Counting

I keep seeing this drawing online and am reading the myriad of answers.  The question is::

HOW MANY SQUARES DO YOU SEE? 

Most people are saying 26.  They are counting these squares that I have numbered here:

18 + 8 = 26

But MORE squares can be found when putting four blocks together to make a 2 x 2 square.  Which can be done 9 times:

Notice I chose a different color to represent each 2x2 square.

THEN, there are the squares that can be made using 9 blocks

for a square measuring 3 x 3:

 

There are FOUR 3x3 squares (each labelled in a different color)

Finally, there is the most obvious square, which is often the most missed.  The large 4 x 4 square:

SO let's add them all up:  

18 + 8 + 9 + 4 + 1 = 40

40 squares.  

Now, there are others coming up with larger numbers.  I can not see more than 40 right now, but would love to be proved wrong on this count.  

:)