观察下列各组数的规律,在横线里填上适当的数. ①1,1,2,3,5,8,_,_. ②3,9,27,81,_,_,2187. ③1,4,9,16,25,_,_.

问题描述:

观察下列各组数的规律,在横线里填上适当的数.
①1,1,2,3,5,8,______,______.
②3,9,27,81,______,______,2187.
③1,4,9,16,25,______,______.

①5+8=13,8+13=21
数列为:1,1,2,3,5,8,13,21.
②81×3=243,243×3=729,
数列为:3,9,27,81,243,729,2187.
③62=36,72=49,
数列为:1,4,9,16,25,36,49.
故答案为:①13,21;②243,729;③36,49.