Jump to content
Science Forums

Number sequence


anto

Recommended Posts

Just b/c I feel like it Ill give one of the answer I came up with..which of course was wrong, but I just want to share one of the ideas I had

finally I found something ion common between the differences (need to multiply times negative three to get the next term) so multiplying by negative three and doing the math you get 125 which is of course, wrong

I don’t understand how you decided on 125.

 

You got this difference table for the given sequence

 1 2 4 8 15 30  50 100
  1 2 4  7 15  20  50
    1 2  3  8   5  30
      1  1  5  -3  25
         0  4  -8  28
            4 -12  36
              -16  48
                   64

The difference table for the sequence extended by a 125 is

 1 2 4 8 15 30  50 100  125
  1 2 4  7 15  20  50   25
    1 2  3  8   5  30  -25
      1  1  5  -3  25  -55
         0  4  -8  28  -80
            4 -12  36 -108
              -16  48 -144
                   64 -192
                      -256

I don’t see a pattern, or understand what you mean by multiplying by -3 to get the next term.

 

Help, please!

 

PS: notice how wrapping tables done in a fixed-width font in code tags (# on the edit toolbar) can display them nicely.

Link to comment
Share on other sites

couldnt figure out how to do them nicely:)

 

Ok so my last line was 4 (-12) and 36 so the next term is -108

 

28 + -108 is -80

 

25 plus -80 is -55

 

30 + -55 is -25

 

50 + -25 is 25

 

100 + 25 is 125

 

 

Here is the complete table

 

1 2 4 8 15 30 50 100 125

 

1 2 4 7 15 20 50 25

 

1 2 3 8 5 30 -25

 

1 1 5 (-3) 25 -55

 

0 4 (-8) 28 -80

 

4 (-12) 36 (-108)

Link to comment
Share on other sites

Is it this sequence? When I factored all the numbers into a product of primes, I get some kind of funky pattern going on. I like the symmetry to it anyway. Thought I'd seen this before somewhere, just thought I ought to throw it out there.

 

1         11 11      1,2,3,5  
2         12 11 
4         12 12   
8         22 12  
15        11 35
30        12 35  
50        12 55  
100       22 55  
49        11 77      7,11,13,17 
98        12 77 
154       12 7(11)
308       22 7(11)
221       11 13(17)
442       12 13(17)
578       12 17(17)
1156      22 17(17)
361       11 19(19)  19,23,29,31
722       12 19(19)
874       12 19(23)
1748      22 19(23)
899       11 29(31) 
1798      12 29(31)
1922      12 31(31)
3844      22 31(31)
 

Link to comment
Share on other sites

Cmon people have we given up?? We now know it has to be less than 100, so our approach to it may change a bit.

I can't find a solution that fits all the criteria. I am interested to see what the answer is, because the criteria of being something a 5th grader could do with their basic understanding of math rules out complex or abstract solutions.

 

It is time for your source to put up or admit it is an exercise of futility to get people to think about math.

 

Bill

Link to comment
Share on other sites

Bill, knowing him i am 100% sure there is an answer. So yeah its obviously very complex in its simplicity I guess b/c you only need to use basic math to get to an answer and still it seems almost impossible to get one. However, even though something is difficult doesnt make it impossible.

Link to comment
Share on other sites

oh guys I totally forgot to mentions this..Due to pgrmdave's post I talked to my calc teacher about the answer. He admitted that the answer is not PURELY mathematical, meaning the numbers can be applied to something else, he said something about it being applied to a social medium or something..

 

ok so lets start thinking about how to relate these numbers to something not related to math.

 

I know this is frustrating..:shrug:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...