If - 1,5,... - 1 Then the 1000th number is (?) and 2011 is (?)

If - 1,5,... - 1 Then the 1000th number is (?) and 2011 is (?)

The sign is + - + -
So the even number is positive and the odd number is negative
If you don't look at the sign, it's the nth odd number
So the 1000th number is - (2 × 1000-1) = - 1999
In 2011, it was 2 × 2011-1 = 4021

Fill in the blanks according to the rules: fill in the blanks with negative - 4710, fill in the blanks, and the number of fields in this column is 100

-1-3 = - 4 - 4 + 11 = 7 7 + 3 = 10 fill in the blanks: 10-11 = - 1 - 1-3 = - 4 this is a cyclic sequence of four numbers, 100 △ 4 = 25 is just to the end of the cycle, and the 100th number is 10

Fill in the blanks according to the order of the following numbers: 1, - 3,5, - 7,9, - 11 The 100th number is

The answer is - 199
1: 2 ^ 1-1 = 1, the degree is singular, and the result is positive;
-3: 2 ^ 2-1 = - 3 the number of times is even and the result is negative;
5: 2 ^ 3-1 = 5, the number is singular, and the result is positive;
-7: 2 ^ 4-1 = - 7 is an even number, and the result is a negative number;
……
The 100th number: 2 ^ 100-1 = 199 the number of times is even and the result is negative; so it is - 199

Fill in the blanks - 1, - 4, - 7,10 (), () The 100th number in this column is

Take out the negative sign, this is a set of arithmetic sequence with tolerance of 3. The rule of the sequence is the n power of (- 1) multiplied by (3n-2). When n = 100, the 100th number is 298

Observe the rule of the number in the following column and fill in the blank: 0, 1, 3, 6, 10,..., then his number 2012 is () and the number n is

A 2-a1 = 1, a3-a2 = 2, a4-a3 = 3.an-an-1 = n-1 add the two sides of the above equations to obtain a2-a1 + a3-a2 + a4-a3 +. An-1-an-2 + an-an-1 = an-a1 = an = 1 + 2 + 3 +... N-1 = (n-1) n / 2 replace n = 2012 with an = (2012-1) * 2012 / 2 = 1006 * 2011 = 2023066, and the nth number is (n-1) n / 2

Can you write down the number of 2012? 1, - 1 / 3,1 / 5, - 1 / 7,1 / 9, - 1 / 11_____ ,______ ,______……______ (number 2012)

1/13,-1/15,1/17
-1/4023

The number of a column arranged in order is given: 1, - 3,5, - 7,9 Write the sixth number______ The 2009 number in this column is______ .

Let's look at the symbols first: odd sign is positive, even sign is negative,
Then the sixth number is even, so it is - (2 × 6-1) = - 11,
From this we can get the regular formula as follows: if it is an even number, then - (2n-1); if it is an odd number, then 2N-1,
Because 2009 is an odd number, the 2009 number of this column number is 2 × 2009-1 = 4017
So the answer is: - 11; 4017

Given the number of a column arranged in order: 1, - 3,5, - 7,9 ·······, what is the 10th number and what is the 2009 number

Let's first look at the sign that the odd sign is positive and the even sign is negative
The tenth number is even, so it is - (2 * 10-1) = - 19
Similarly, 2009 is positive, so it is (2 * 2009-1) = 4017

1. Give the number of a column arranged in order: 1, - 3,5, - 7,9 The 2000th number in this column is () 2. Draw a number axis first, and the chess pieces fall on the A0 point on the number axis. The first step is to jump 1 unit length from A0 point to A1, the second step is to jump 2 unit length from A1 to A2 left, the third step is to jump 3 unit length to A3 from A2 to the right, and the fourth step is to jump 4 unit length from A3 to A4 If A50 means 26, what number does A0 represent?

1-3999
2000 is an even number and a negative number. There is a second beginning, and the difference between the number of digits and the number is one. So the 2000 number is 2000 and 1999. It is - 3999
The number represented by 2ao is 51 -25 pairs of digits 1 and 2 add up to - 1, which means - 25.26 plus 25 makes 51

Find the rule - 1 - 1 / 3 1 / 5 1 / 7 - 1 / 9 - 1 / 11 1 / 13 1 / 15 the 2005 number and the 2008 number Anxious ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ good answer, I will increase the reward

Let's not talk about the sign
The rule is 1 / (2n-1)
2005 number 1 / 4009
2008 1/4017
Starting with five terms, if (n-1) / 4 or (n-2) / 4 is an integer, it is negative, and the others are positive
therefore
Number of 2005 - 1 / 4009
2008 1/4017