What Comes Next in This Number Sequence?

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Discussion Overview

The discussion revolves around identifying the next number in a complex number sequence, which appears to involve patterns related to partitions and relationships between even and odd numbers. Participants explore various hypotheses and reasoning related to the sequence's structure, including mathematical operations and relationships among the numbers presented.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that the next number could be 8, based on observed patterns in the sequence.
  • Others suggest 16, arguing that it follows a multiplication pattern involving the previous numbers.
  • A later reply questions the validity of the previous answers, indicating that none are correct and suggesting that the sequence may require more information.
  • Participants discuss the concept of partitions, with one explaining that a partition represents a positive integer as a sum of other positive integers.
  • Some participants explore the idea of decomposing fractions and how they relate to the sequence, noting that certain numbers are left intact when followed by a prime number.
  • Another participant identifies a pattern involving the differences of factors of numbers, suggesting a systematic approach to understanding the sequence.

Areas of Agreement / Disagreement

There is no consensus on the next number in the sequence, with multiple competing views and interpretations of the patterns presented. Participants express uncertainty and continue to refine their hypotheses without reaching a definitive conclusion.

Contextual Notes

Participants acknowledge limitations in their understanding of the sequence, with some suggesting that additional clues or information may be necessary to arrive at a correct answer. The discussion reflects a variety of mathematical reasoning approaches and interpretations of the sequence's structure.

Who May Find This Useful

Individuals interested in number theory, mathematical patterns, and problem-solving may find this discussion engaging and thought-provoking.

Moo Of Doom
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1
1
2
1 2
4
1 1 3
6
1 2 4
?

What comes next?
 
Mathematics news on Phys.org
Moo Of Doom said:
1
2
1 2
4
1 1 3
6
1 2 4
?

What comes next?

Answer (in white):
8 (a partition of 8, but the even numbers are partitioned into a single partition). I haven't figured out how the odd numbers are partitioned, but it seems that the entry for 2^n - 1 is 1 2 4 ... 2^(n-1)
 
Nope, that's not it. But that's an interesting observation about the partitions! I hadn't noticed that.
 
8, i am not sure what the real pattern is but looking from the most left number in each line, 1,2,1,4,1,6,1,... one could easily guess 8
 
Worth a shot.
[Answer in white]

Answer: 16

It increases the first number by one then multiply it with the rest.
ie:
1 2 4
(1+1) * 2 * 4 = 16
[/color]
 
Spoiler warning:

The answer is 16. Or so I think, if my way is allowed.

1
2
1 2
4
1 1 3
6
1 2 4
?

separate the lines into groups just to understand it better:

1
2
--------
1 2
4
--------
1 1 3
6
------
1 2 4
?

Multiply the top lines digits by themselves and then by two:
(a*b)*2

so the first line:
(1)*2=2

and the second & third:
(1*2)*2=4

(1*1*3)*2=6


So for the bottom line you get:
(1*2*4)*2=16



Is that a logical answer?
 
so you are saying that the top line in each group generated by random ?
 
Nope, none of the answers so far are correct. Jimmysnyder was the closest with his comment about the partitions.

Maybe there isn't quite enough information.

Here's the pattern a bit longer:

1
2
1 2
4
1 1 3
6
1 2 4
2 6
1 3 5
10
?

What comes next?
 
Moo, how about more clues, or an answer?
 
  • #10
Sure. Here's quite a bit more of the sequence:

1
2
1 2
4
1 1 3
6
1 2 4
2 6
1 3 5
10
1 1 1 2 6
12
1 5 7
?

Still want a clue? Partitions are correct. But think of the sequence as starting from 2 rather than 1...
 
  • #11
a 16 year olds guess...lol



4 10
1 2 4 8
16


??
 
Last edited:
  • #12
Close. The second two are correct, but 4 10 is not. Care to explain your answer?
 
  • #13
ummm lol nope - I am not good at explain them

ok its sumthin like 4 10...but the numbers add up to 14? i spent about 20 mins workin it out lol ill get it when i get time
 
  • #14
Yeah, the numbers add up to 14 but they're not 4 10.
 
  • #15
is it 2 12?
 
  • #16
and *this is gna seem really stupid* but what's partition?
 
  • #17
0m3ga said:
and *this is gna seem really stupid* but what's partition?
A partition is simply a representation of a positive integer as a sum of other positive integers. For instance 12 = 2 + 10 or 12 = 4 + 8, or 12 = 1 + 2 + 9 or in the degenerate case, 12 = 12. The sequence that Moo has presented us with can be viewed as a sequence of partitions. Here is a list of all the possible partitions of 5:

5 = 1 + 1 + 1 + 1 + 1
5 = 1 + 1 + 1 + 2
5 = 1 + 1 + 3
5 = 1 + 4
5 = 1 + 2 + 2
5 = 2 + 3

I hope I didn't miss any. By the way, I didn't know what a partition was until I was about 21, so now you are 5 years ahead of me.
 
  • #18
0m3ga said:
is it 2 12?
Nope. First number is 2, though.
 
  • #19
the only reasonable guess i can think off is 2 6 6
 
  • #20
Now you're just firing blindly :P

Nope, not 2 6 6.
 
  • #21
lol yeah howd you guess

i see the whole pattern the only bit i didnt get was the bit where it went 2 6 lol and I am guessin that's linked to the line i can't get
 
  • #22
Looking at your pattern I think it has something to do with the factorisation of the next number

I can see that each number that is followed by a prime number is left intact

I think it is based on some method of decomposing the fractions

1/2, 2/3, 3/4, 4/5 etc

I notice that 2/3 can't be broken down
but 3/4 = 1/2 + 1/4
7/8 and 15/16 seem to match your breakdown

when I do 8/9=2/3+2/9 it seems to confirm your partition pattern

BUT

9/10=1/2 +4/10 DOESN'T match up

So I'm missing some other criterion that is not apparent
 
  • #23
Let's see here:

2 3 10
1 2 4 8
16
1 1 3 3 9
18
[/color]
 
  • #24
NateTG has almost got it. His 2 3 10 doesn't add to 14, though... so that's not quite right. Everything else is correct though.
 
  • #25
2 2 10?...
 
  • #26
0m3ga said:
2 2 10?...

Yes!

Now someone explain the pattern... :)
 
  • #27
take any 2 subsequent even numbers from the sequence (e.g. 2 and 4) and the number between will = the smaller even number/the bigger even number

2
1 2
4

2/4=1/2

every odd number is written as a fraction where the last number os the denomenator and the sum of the rest equal the numerator e.g in the case of 1 1 1 2 6 = (1+1+1+2)/6

the other pieces i can't remembe right now lol someone else can finish it off
 
  • #28
The numbers are differences of the factors of n+1:

The factors of 15 are:
15,5,3,1
10=15-5
2=5-3
2=3-1

The factors of 16 are
16,8,4,2,1
8=16-8
4=8-4
2=4-2
1=2-1

The factors if 17 are
17,1
16=17-1

The factors of 18 are:
18,9,6,3,2,1
9=18-9
3=9-6
3=6-3
1=3-2
1=2-1

(It's pretty straightforward to show that this will always add up to n.)
 
  • #29
Congratulations, NateTG! 100% correct answer. That is the origin of the pattern indeed.
 

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