2*3*4*5+ 1= 12 1

3*4*5*6+ 1=36 1

Please find out its pattern.

Multiply the first number of four consecutive multipliers by the fourth number and add 1 to get the square of the number. For example: 6 * 7 * 8 * 9+1= (6 * 9+1) 2 = 3025.

Two: Here is a set of numbers arranged according to certain rules.

1/ 10, 1/ 1, 1/ 12, ... 1/ 19, 1/20.

Because the problem is at least, the less the better. Therefore, the quantity should be large. First, the first six digits are calculated by the method of "adding the first item to the last item and dividing the multiplied item by 2". Add the last 20% 1 to see if it can be greater than 0.5, and it will be OK.

3: The serial numbers of a column are 1, -3.5,-7,9, 1 1,-13, etc. So what is the number 100th in this column?

-1 times 2 (n-1)+1.

The 100th number of this column:-1 (100- 1) times 2 (100-1)+1,that is,-/kloc-.

In fact, it is only two parts:

The preceding symbols have signs alternately:-1 to the power of (n- 1).

The following values are odd: 2(n- 1)+ 1.

Four: 1, 4,21,56, 1 15, ()

2,30, 130,350,()