题目

He is a Time Lord who can travel anywhere he wants in time, but still never seems to be happy. He is always very well dressed. He refuses to use guns to kill anybody, preferring to trust his brains.Who could be a better hero for British people? He is the Doctor, hero of the popular BBC TV series Doctor Who, which celebrated the 10th anniversary of its 2005 reboot on March 26. In 2005 the sci-fi TV series returned to British screens after originally running from 1963 until 1989. In the series, the Doctor travels through time in his TARDIS police box，saving Earth and other planets from 如图①是一块瓷砖的图案，用这种瓷砖来铺设地面，如果铺成一个2×2的正方形图案(如图②)，其中完整的圆共有5个，如果铺成一个3×3的正方形图案(如图③)，其中完整的圆共有13个，如果铺成一个4×4的正方形图案(如图④)，其中完整的圆共有25个，若这样铺成一个10×10的正方形图案，则其中完整的圆共有________个．