2 6 18 51 162 what's the rule?

2 6 18 51 162 what's the rule?

If it's 2, 6, 18, 54162, their rule is that the former number is multiplied by 3 to get the latter number
For example, 2x3 = 6 5x3 = 18 18x3 = 54 54x3 = 162
I don't know if you copied the wrong question

51.26.4 0.8 () find out the regular filling number

Previous number △ 8 = next number
therefore
51.2 6.4 0.8 （0.1）

25 2.51 () () 0.625

The title must be wrong!
Should be:
6.25 2.5 1 (0.4) (0.16) 0.064
The last number is equal to 0.4 times of the previous number

Find the rules 15,21,18,19,21,17, (), ()

1 3 5 increase
24 6 decline
So fill in 24, 15
Do the task,

1 2 6 7 15 16... 3 5 8 14 17... 4 9 13 18... 10 12... 11... The number 3 is in the first column of the second row, In the third row and third column, ask: which row is 1993 in?

(1) (2) (6) (7) (15) (16)... (3) (5) (8) (14) (17)... (4) (9) (13) (18)... (10) (12)... (11)... Turn right to get the following arrangement: (1) (3) (2) (4) (5) (6) (10) (9) (8) (7) (11) (12) (13) (14) (15). (18) ()

Quality cup 3,4,6,8,12,14,18,20,24, What is the number after 24, and the answer is 30,

3,4,6,8,12,14,18,20,24,
Every number is 1 + prime
1+2=3
1+3=4
1+5=6
1+7=8
1+11=12
1+13=14
1+17=18
1+19=20
1+23=24
1+29=（30）
1+31=32
1+37=38
1+41=42
...

A simple algorithm for finding 200-20-19-18-17-16-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1 A simple algorithm for finding 200-20-19-18-17-16-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1

200-（20+19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1）
=200-【（20+1）*10】
=200-210=-10

1 3610 15 21 28 259 14 20 27 48 13 19 26 7 12 18 25 11 17 24 16 23 22 observation array, 2010 in the row No The following is the original question: 1 3 6 10 15 21 2 5 9 14 20 4 8 13 19 7 12 18 11 17 Sixteen What row and column is 2010 in?

7 rows and 57 columns
From the given matrix, we can think of this matrix as an equilateral triangle, the number of values on each side is set to N, and then we can see that the value of the upper right corner of each equilateral triangle is the largest, and it also conforms to the Gauss summation formula n (n + 1) / 2 / 2. Next, we use the hypothesis method to assume that 2010 is the value of the uppermost right corner, and then we have n (n + 1) / 2 = 2010, and calculate n = 63.4, and we take the integer n = 63 So we can calculate that when the number of each side is 63, the value of the upper right corner of the equilateral triangle is 2016. Now, we all know how to do this step

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 ……… Find the sum of the numbers in the nth row

n*59 n×n

2.4.10.18.28.82( ) ( )

2.4.10.18.28.82.116.198