All sequence riddles are wrong .why?

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Discussion Overview

The discussion revolves around the nature of sequence riddles, particularly questioning their validity and the uniqueness of their solutions. Participants explore the mathematical relationships within sequences, the potential for multiple interpretations, and the subjective nature of determining the "correct" next term in a sequence.

Discussion Character

  • Debate/contested
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • Some participants argue that sequence riddles lack a unique answer because they can be interpreted in various ways, depending on the mathematical relationships applied.
  • Others propose that any given sequence can be fitted with a polynomial of n+1 points, leading to an unlimited number of possible answers.
  • A few participants highlight that the simplest solution is often preferred, but there is disagreement on what constitutes "simplicity."
  • One participant shares an anecdote about a sequence that had a non-intuitive answer based on contextual information, illustrating the subjective nature of interpreting sequences.
  • There is a discussion about the limitations of polynomial fitting, with some asserting that only certain degrees of polynomials can be derived from a given number of points.
  • Participants express skepticism about the validity of certain solutions, questioning whether all curves fitted to points represent legitimate answers to the riddle.
  • Some participants mention that the aesthetic appeal of a solution may influence its acceptance as the "best" answer.

Areas of Agreement / Disagreement

Participants generally agree that there is no unique answer to sequence riddles, but multiple competing views remain on how to approach these sequences and what constitutes a valid solution. The discussion remains unresolved regarding the criteria for determining the "simplest" or "best" answer.

Contextual Notes

Participants express various assumptions about the nature of sequences and the rules governing them, which may not be universally accepted. The discussion reflects a range of interpretations and the potential for ambiguity in defining terms and relationships within sequences.

  • #31
You don't even have to do fit to a polynomial fit, sequences do not have to have rules, so the next term in the sequence can be whatever you want it to be.
 
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  • #32
DavidWhitbeck said:
You don't even have to do fit to a polynomial fit, sequences do not have to have rules, so the next term in the sequence can be whatever you want it to be.

Fair point. So the next member of "1, 2, 4, 8, 16, 32" could be "dragon".
 
  • #33
Here's an idea for a sequence riddle: given a countable sequence of natural numbers, what ordinals come next?

Say N=(1, 2, 3, 4, ...), I could say what comes next are all ordinals. OR I could say that what comes next are all SINGULAR ordinals, etc.
 
  • #34
Thats good!

Very interesting thread...

I have had some research (not a serious one) on the polynomial sequences when I was in high school. I know this is not exactly what you are looking for but this is what you might find interesting.

I found a single function definition which would do all the work you have been doing in post#1,

I have attached the function to the post as a jpg.

n represents the degree of the polynomial
delta "x" can be anything
"C" represents combinations.

______

comments will be highly appreciated
 

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  • Law 1.JPG
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  • #35
CRGreathouse said:
Fair point. So the next member of "1, 2, 4, 8, 16, 32" could be "dragon".

No because sequences are by definition subsets of N.
 
  • #36
DavidWhitbeck said:
No because sequences are by definition subsets of N.

Those are natual number sequences

There are real sequences like
3,3.1,3.14,3.1415,3.1415926,3.141592653...
rational seqences
.1,.11,.111,.1111,.11111,...

A sequence is a mapping of the natural numbers to an arbitrary set
or if one prefers
we can define a seed and a map f:S->S
ie
seed=a0
a1=f(a0)
sucsessor(an)=an+1
f^n(seed)=an
 
  • #37
All this said there is some value in trying to choose a best in some sense sucsession function given a run of a sequence
thhe trouble is knowing which sense our some sense should be
 
  • #38
lurflurf said:
A sequence is a mapping of the natural numbers to an arbitrary set
or if one prefers
we can define a seed and a map f:S->S

Oops not general enough
we will just go with
f:N->S
S an arbitrary set
so maybe we have

1,2,3,4,5,...,88,89,pickles
 
  • #39
lurflurf said:
A sequence is a mapping of the natural numbers to an arbitrary set
n

I may just be playing devil's advocate, but who says sequences have to be infinite?

1, 3, 4, 6, 8 ...

what comes next? perhaps the answer is undefined, or nothing.
 
  • #40
good point there are I speak of one popular sequence there are also
finite sequences
double sequences
sequences over other index sets like
Moore-Smith sequences

many times the tradition sequence structure can be used
such as
11/8,9/7,7/6,5/5,3/4,1/3,-1/2,-3/1,-5/0,-7/-1
we could interpet formally, or if it is to be interpeted as division well could mark problems as "undefind" which we could ad to the domain

for finite sets we could repeat the final entry of append a sybmol
1,2,3,4,5
could be
1,2,3,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,...
0r
1,2,3,4,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,...
or
1,2,3,4,5,done,done,done,done,done,...
 

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