找规律填数字:1,1,3,7,17,41()a.89,b.99,c.109,d.119,要找规律填数字:1,1,3,7,17,41()a.89,b.99,c.109,d.119,要分析为什么选它

Question

找规律填数字:1,1,3,7,17,41( ) a.89,b.99,c.109,d.119, 要
找规律填数字:1,1,3,7,17,41( )
a.89,b.99,c.109,d.119,
要分析为什么选它

Answer 1

找规律填数字:1,1,3,7,17,41( b.99 )
后面的数=它前一个数的2倍加上它前面的前面那个数
3=1×2+1
7=3x2+1
17=7x2+3
41=17x2+7
99=41x2+17