Place squares of the same size according to the following rules and color the overlapping parts. In the following pattern, the number of squares in the nth pattern is (4×n- 1). Analysis: observing the pattern, it is found that there are 3 squares in 1 pattern; In the second mode,

There are 3×2+ 1=7 squares; In the third pattern, there are 3×3+2= 1 1 squares ... and so on, that is, on the basis of three, there are four squares behind, so the number of squares in the nth pattern is 4n- 1.

Solution: According to the meaning analysis, the number of squares of 1 pattern is 4× 1- 1=3, the number of squares of the second pattern is 4×2- 1=7, and the number of squares of the third pattern is 4× 3-65448.