Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
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As your posts will be visible to the general public you are requested to be thoughtful in not posting anything that might explicitly give away how to solve a particular problem.
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Don't start begging others to give partial answers to problems
Don't ask for hints how to solve a problem
Don't start a new topic for a problem if there already exists one
See also the topics:
Don't post any spoilers
Comments, questions and clarifications about PE problems.
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hughbert_cumberdale
- Posts: 9
- Joined: Thu Apr 09, 2026 7:54 am
Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
I'm working on the bonus problem about negatively continued fractions, does the set of coefficients have to repeat immediately or can there be a non-repeating section first?
- neverforget
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- Joined: Sat Sep 16, 2006 10:10 pm
Re: Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
Periodic negatively continued fractions have no non-repeating section.

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hughbert_cumberdale
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Re: Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
Great thanks. This is a hard question, there seems to be very little written about negatively continued fractions so it's hard to learn the number theory for it. My code gives the wrong answer and only takes 13 hours 
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hughbert_cumberdale
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Re: Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
Another question, it's not clear to me if repeated sequences are valid, for example if 1,2 is a complex sequence, and 1,2,1,2 is also complex, then do we count both? Because by my calculations, 1,1 is a complex sequence but in the example it says that the only complex sequences that are 2 elements long are 1,2 2,1 1,3 and 3,1.
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pjt33
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Re: Bonus problem 0 - 1/ (0 - 1 (0 .... (called #contfrac in browser tab)
They are infinite periodic sequences, so $\overline{1, 2}$ and $\overline{1, 2, 1, 2}$ are the same sequence and should only be counted once.hughbert_cumberdale wrote: Mon Jun 01, 2026 11:50 pm Another question, it's not clear to me if repeated sequences are valid, for example if 1,2 is a complex sequence, and 1,2,1,2 is also complex, then do we count both?