36,28,21,15,10,6,3,1?

Question

What do these patterns of numbers represent? It's a pattern I've seen before...

I think I found it. The triangle formula....

Answer 1

They are also called triangle numbers, because you can arrange marks on a page in the shape of a triangle for each number. For example here are 28 marks:

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Note that to create this pattern with 28, the last row has 7 marks. If we remove that last row, we end with a row of 6, and the total number of marks is 21, the next number on your list.

Answer 2

First factor repeats then decreases by one. Starts with the number 4. The second factor repeats then decreases by two. Starts witht he number 9.
36 = 4 * 9
28 = 4 * 7
21 = 3 * 7
15 = 3 * 5
10 = 2 * 5
6 = 2 * 3
3 = 1 * 3
1 = 1 * 1
So to get the number before 36 it would be 5 * 9 which is 45

Answer 3

The difference between the number and the next is its position/index. i.e
x0 = 0 (you're missing it)
x1 = 0 + 1 = 1
x2 = 1 + 2 = 3
x3 = 3 + 3 = 6
x4 = 6 + 4 = 10
...
xn = x(n-1) + n
I don't remember what this type of sequence is called

Answer 4

that's easy :]

you see here:

36-8=28
28-7=21
21-6=15
15-5=10
10-4=6
6-3=3
3-2=1

so you add 1 and 1[the first counting number] then add the result to 2[which is the second number] which will result to 3. then the same pattern follows. *sorry if this part is quite confusing

Answer 5

They are triangular numbers and can be found using the formulae: a(n) = C(n+1,2) = n(n+1)/2 = 0+1+2+...+n.

Answer 6

36-8=28-7=21-6=15 and so on

Answer 7

subtract each number from the previous one and you will see the pattern

Answer 8

Subtract 8, then 7, then 6, then 5 ....

Answer 9

zero

what they represent? no clue - but the difference between one number and the next is reduced by one each time.