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Timeline for Periods of Continued Fractions

Current License: CC BY-SA 2.5

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Apr 13, 2017 at 12:58 history edited CommunityBot
replaced http://mathoverflow.net/ with https://mathoverflow.net/
Aug 6, 2010 at 16:49 comment added Joseph Malkevitch Ideas in this paper might be of use: math.princeton.edu/mathlab/jr02fall/Periodicity/periodmain.htm
Jul 23, 2010 at 6:46 history edited Gerry Myerson CC BY-SA 2.5
corrected spelling
Jul 23, 2010 at 6:43 comment added Gerry Myerson @Franz, "$a$ or $b$" is equivalent to "$b$ or $a$", so the way I interpret it, the right side of the equation is certainly invariant under switching $p$ and $q$.
Jul 23, 2010 at 0:00 answer added Gerry Myerson timeline score: 3
Jul 22, 2010 at 8:06 comment added Franz Lemmermeyer Let me add the remark that the left hand side of the equation in your question is invariant under switching p and q, but the right hand side is not. Thus you can't really expect it to hold.
Jul 22, 2010 at 0:21 comment added Will Jagy Read the comments after Franz's answer, he revised that part of it. I will run some experiments. But bear in mind that sometimes your $l(pq)$ will be roughly the size of $l(p) \cdot l(q)$ which is consistent with some very simple bounds of Lagrange. But I bet that there are infinitely many instances of $$ p \cdot q = n^2 + 1 $$ which has about the shortest continued fraction period. That is, consider $$ \sqrt{10}, \; \sqrt{26}, \; \sqrt{65}, \; \sqrt{82}, \; \sqrt{122}, \; \sqrt{145}, \; \ldots \sqrt{901}, \; \ldots $$ where $901 = 17 \cdot 53$ was the first not divisible by 2 or 5.
Jul 22, 2010 at 0:06 comment added Gerry Myerson It should be easy enough to check this for a few primes. Did you?
Jul 21, 2010 at 23:53 history edited Wadim Zudilin CC BY-SA 2.5
improved; deleted 1 characters in body
Jul 21, 2010 at 23:25 history asked Jerald Jetson CC BY-SA 2.5