14. A heptagonal board is shown in Figure 4, with 7 vertices numbered from 0 to 6, referred to as seven cells. A piece is placed in cell 0. Now, move this piece counterclockwise, moving 1 cell the first time, 2 cells the second time, $\cdots \cdots$ $n$ cells the $n$-th time. Then the cells where the piece does not stop are numbered
14.2,4,5.

Try to find:
(1) The squares where the chess piece never stops are $2,4,5$;
(2) The number of the square where the chess piece stops repeats every 7 moves (i.e., the $k$-th move and the $(k+7)$-th move stop at the same square).
Proof: On the $k$-th move, the number of squares moved is
$$
1+2+\cdots+k \text {. }
$$

On the $(k+7)$-th move, the number of squares moved is
$$
1+2+\cdots+k+(k+1)+\cdots+(k+7) \text {. }
$$

And $[1+2+\cdots+k+(k+1)+\cdots+(k+7)]-$
$$
(1+2+\cdots+k)=7 k+28=7(k+4) \text {, }
$$

Therefore, the $(k+7)$-th move and the $k$-th move stop at the same square.