Write the general term formula. (1) 1 / 2; 3 / 4; 5 / 6; 7 / 8;... (2) 3; 5; 9; 17; 33... (3) 6; 66; 666; 6666... (4) 1,2,4,3,8,4,16 Write the general formula (1)1/2;3/4;5/6;7/8;... (2)3;5;9;17;33... (3)6;66;666;6666... (4)1,2,2,4,3,8,4,16,5... (5)-1,1,-1,1,-1,1...

Write the general term formula. (1) 1 / 2; 3 / 4; 5 / 6; 7 / 8;... (2) 3; 5; 9; 17; 33... (3) 6; 66; 666; 6666... (4) 1,2,4,3,8,4,16 Write the general formula (1)1/2;3/4;5/6;7/8;... (2)3;5;9;17;33... (3)6;66;666;6666... (4)1,2,2,4,3,8,4,16,5... (5)-1,1,-1,1,-1,1...

(1)an=(2n-1)/(2n)
(2)an=2^n+!
(3)an=(2/3)×(10^n-1)
(4)an=(n+1)/2,(n=2k-1)
An = 2 ^ (n / 2), (n = 2K), where k is a positive integer
So we construct a general term: an = {[1 + (- 1) ^ n] / 2} * 2 ^ (n / 2) + {[1 + (- 1) ^ (n + 1)] / 2} * [(n + 1) / 2]
(5)an=(-1)^n

Find out the arrangement of the numbers in the following series and fill in the appropriate numbers on the horizontal line
            7,14,10,12,14,9,19,5,——,——
           7,8,10,——,22,38
             5,14,41,122——
              1,2,2,4,8,32——
Sequence 1, - 1 / 3,1 / 5, - 1 / 7,1 / 9 The general term formula of an=——

（1）7,14,10,12,14,9,19,5,25,0
The odd sequence and even sequence can be seen separately
Odd column:
7+3=10
10+4=14
14+5=19
So the next number is:
19+6=25
Even sequence rule:
14-2+12
12-3+9
9-4=5
So the next number is:
5-5=0
（2）7,8,10,14,22,38
The rule is as follows
7+1=8
8+2=10
10+4=14
14+8=22
22+16=38
（3）5,14,41,122,365
The rule is as follows
5+9=14
14+27=41
41+81=122
So the next number is:
122+243=365
（4）1,2,2,4,8,32,256
The rule is as follows
1*2=2
2*2=4
2*4=8
4*8=32
8+32=256
The latter is the product of the former two
（5）an=[（-1）^(n+1)]/(2n-1)

The following series of poems are arranged according to a certain rule. Fill in the numbers according to this rule: 3, 5, 9, (), 33, 65
Such as the title

17
Multiply the preceding number by two minus one