3 out of 1.9, 4 out of 12, 5 of 15, 6 of 18, 2.8, 2, 1 of 8 and 1 of 32 3.1、4、9、16、25、【】、49、64

1） 7/21
2） 1/2
3） 36

Fill in 163 8 94 ()（

27,2
The general formula is
An = 2 ^ [5 - (n + 1) / 2] (n is odd)
An = 3 ^ (n / 2) (n is even)

Fill in 1, 16, 3, 8, 9, 4, (), ()

27 2
1 3 9 3^3=27
16 8 4 4/2=2

1638 649 () () find out the regular filling number 16 3 8 6 4 9 ( ) ( )

16 3 8 6 4 9 (2 ) (12 )
16 8 4 /2
3 6 9 +3

Fill in the numbers: 1, 2, 4, 8, 16, () Fill in the brackets

1、2、4、8、16、（32）
The latter is equal to 2 divided by the former

1 / 4, - 1 / 4,3 / 16, - 1 / 8,5 / 64, find the rule and fill in the numbers. What are the last two

1/4,-1/4,3/16,-1/8,5/64,(-1/16),(7/256)
law:
The numerator is 1,3,5... The growth difference is 2, and the denominator is 4,16,64;
The even digit is negative, the numerator has no change, all are 1, the denominator is multiplied by 2, so the sixth number is (- 1 / 16)

Fill in the numbers 4,0,4,4,8,12, (), ()

20 32
The last number is equal to the sum of the first two

Fill in the number 258 127 Fill in the number 258 12 7 6 7 28 1 1 () 13 3 13 16 60 30 () 80

Could you send out the pictures, please

Fill in 1, 2, 3, 6, 11, 20, (), () and 2, 3, 5, 6, 8, 12 (), ()

1）
Solution 1 + 2 + 3 = 6
2+3+6=11
3+6+11=20
6+11+20=37
11+20+37=68
So fill in 37 68
2）
The second law is not obvious
sure
2、3、5、6
8、12（20）、（24）
The last four are four times as much as the first four

2. 8, 5, 20, 7, 28, 11, 44, (), 12, 6, () find the law and find the process

3 24

3 out of 1.9, 4 out of 12, 5 of 15, 6 of 18, 2.8, 2, 1 of 8 and 1 of 32 3.1、4、9、16、25、【 】、49、64