Pretty sure the biggest "gotcha" for people is squares consisting of multiple smaller squares. Unless you've encountered problems like this before, it's not int

Pretty sure the biggest "gotcha" for people is squares consisting of multiple smaller squares. Unless you've encountered problems like this before, it's not intuitive to consider the 2x2 or 3x3 squares (and they might even miss the 4x4). This iteration of the problem is more interesting because of the two inner squares. It simultaneously makes you think you figured it out too early (I got the inner squares AND the tinier squares they were made up of! That must have been the trick!), and suggests the larger problem you might be missing.