<image>Build squares using matchsticks according to the illustrated pattern:

(1) Fill in the table:
\frac{}
(2) If n=10, how many matchsticks are needed?
(3) If 61 matchsticks are used, how many such squares can be formed?
(4) By observing, what relationship do you find between the number of matchsticks (m) and the number of squares (n)? Fill in the blank: m=____ (expressed using a formula with variables)