What is the next number in this series?

-1, 3, 1, -1, 3, ...

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And the winner is

The series satisfies the expression x^3 -3x +1 , starts at x = -2 , and is derived using finite differences.

waitingforgodo
Level 7
Sep 8, 2021

1…and shut the f—k up with the rest of your nonsense.

MsKathleen
Level 8
Sep 8, 2021

Does anyone know the numerical answer to this question?

waitingforgodo
Level 7
Sep 8, 2021

- There's no indication that anything preceded the first -1.

-1, 3, 1, -1, 3,

the next numbers

-1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, 1, -1, 3, and so forth and so on....

Three follows -1, and 1 follows 3 otherwise there's no progression in my solution which is a valid assumption considering the information given.

Prove me wrong.

Willow_Wisp
Level 8
Sep 8, 2021

Harrumph! You ASSume that the information given is complete. (To ASSume, to make an ass out of you and me).

Prove me wrong.

More seriously, the sequence 7,10,17,7,111,26,34,16,24,32,107,14,14,22 ... 41,41,134,134,41,41 ...arises naturally from observations on the Collatz Conjecture.

If the previous term is even, the next term is one half of the previous term. If the previous term is odd, the next term is 3 times the previous term plus 1. The conjecture is that no matter what value of n, the sequence will always reach 1.

So not true to the Collatz Conjecture to begin with.

The Collatz Conjecture has to start with any positive integer n and -1 isn't a positive integer.

There's no even numbers in your sequence.

So I used the kiss principle being a good engineer, since the best designs are always the simplest.

@Willow_Wisp I find it odd that you should say that there are no even numbers in my sequence. Perhaps ternary sequences are more to your taste?

Oh, of kiss: "Keep It Simple, Sweetheart".

And now I am about to be exceedingly rude: the simplest design of the Tay Rail Bridge did not seem to work so well: [en.wikipedia.org] (On a personal note, I once lived not far from the location of that sad event.)

@Willow_Wisp Um, when did negative 1 equal 7? Are you speaking octal?

Fiat? Hold En? De Troit? Trouvé's tricycle?

@anglophone Your poll is, and I quote.

What is the next number in this series?

-1, 3, 1, -1, 3, ...

There's no 7 in the question.

@anglophone Hah! Right you're not even the person that did this dumb ass poll.... LOL

solution and methodology posted above.

- The answer is always 42.

KKGator
Level 9
Sep 8, 2021

Not this time, sweetie.

@MsKathleen Every time. The question doesn't matter.

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