用400个棋子摆放了5层空心方阵，最内层每边有几个棋子？(E+`:m3f2V2w1C
算式：提示/@4f'|5X)])n6Y9o9m3r9D(E+`:m3f2V2w1C
答：最内层每边有4[4]*K5_5Y个棋子。(E+`:m3f2V2w1C