Observe the number of columns: 1,2, - 3, - 4,5,6, - 7, - 8, ····. What are the numbers of 2005 and 2008? Observe the number of columns: 1,2, - 3, - 4,5,6, - 7, - 8, ····. What are the numbers of 2005 and 2008?

Observe the number of columns: 1,2, - 3, - 4,5,6, - 7, - 8, ····. What are the numbers of 2005 and 2008? Observe the number of columns: 1,2, - 3, - 4,5,6, - 7, - 8, ····. What are the numbers of 2005 and 2008?

2005 - 2008 idea: when the number is a cardinal number, divide the even number on its right by 2, and the mantissa is odd, then it is a positive number

If the number of a column arranged according to the law is negative one, two, four, eight, sixteen, thirty-two, then the number of 2012 is

four thousand and twenty-four

What is the law of (5,6,10) (5,12,20) (6,20,40) (9,7), (4,8) （5,6,10）（5,12,20）（6,20,40）（9,）（4，,8) According to the relationship of the first three groups

Multiply the first two and divide by 3 to get the third number
For example, 5 * 6 / 3 = 10, 5 * 12 / 3 = 20, 6 * 20 / 3 = 40,
So the numbers are 21 and 6

5,12,6,10,7,8,（）,（）,（）…… Find the rules

The first, the third, the fifth, the rule is 567. The next one is 8 9 10 11 12 13. The second is 12 10 8, and the next is 6 4 20

Find the rules 4, 9, 8, 6, 5, 10, 7, 8, 10, 15, 11, 15, 12, 18, 13, 9 10 15 18 4 8 5 7 10 11 12 13 6 8 15 Options: A, 15 B, 19 C, 20 D, 23 Ask for a question mark!

I think it's 20. If you look at the title, the sum of four numbers is a multiple of 3. It's an increasing trend! And it's definitely not a prime number. Look at the rule, the prime number is not adjacent! I guess

Find the law: 1, - 3 / 4,4 / 6, - 5 / 8,6 / 10, - 7 / 12 Then the 9th and 10th numbers are respectively. Guess the 1004th number is Thank you for your help!

In fact, it's very simple. For example, according to the above rule, the seventh and the sixth are examples - the seventh should be like this, the denominator is 7 times 2 to get 14, and the numerator is 7 plus 1. As for the plus -, + sign, it depends on whether the number is odd or even, the seventh number, 7 is singular, do not need to add -, +, the sixth, you should add -. As for the sixth, it is - 7 / 12

6 1 8 3 10 5

Even numbers are increased by 2, 5, and 8, respectively

The first line was 2.5.6.7.11, the second line was 8.10, () 4.18, and the third line was 6.10.12.9.20

Multiply the first line by 2:4 10 12 14 22
The second line remains unchanged: 8 10 () 4 18
The third line is all multiplied by 2:12 20 24 18 40
The rule is that the number in the third row is the sum of the first row and the second line, so fill in 12

Find the rule 2,1,4,3,6,6,8,10, (), (), 12,21,14. What do you fill in the brackets?

10 and 15

A column number: - 2,4, - 6,8, - 10,12.. write down the 2009 number according to the rule, which should be?

an＝[（-1）^n]×2n.
a2009＝-2×2009＝-4018