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16 votes
3 answers
4k views

Is it known that the Collatz-like sequence with 7n+1 diverges to infinity starting with 7?

In this question I was wondering if the $3$ in the Collatz conjecture is arbitrary, and when I wrote that question I tried to change to $7n+1$ starting with the seed number $7$, the sequence appears ...
pie's user avatar
  • 541
1 vote
0 answers
158 views

A question and reference about Bombieri's article continued fraction of algebraic numbers

Above the Comments in the article continued fraction of algebraic numbers, there are some words on the unboundedness/cycle of coefficients of continued fraction of algebraic numbers "Thus, ...
XL _At_Here_There's user avatar
2 votes
1 answer
1k views

Reference on the Collatz conjecture [closed]

I'm just looking for references in the literature for some observations I made for fun about the Collatz conjecture. The Collatz conjecture states that any positive integer $n$ can eventually be ...
user140242's user avatar
4 votes
0 answers
504 views

Collatz conjecture and a diophantine equation

Let $M \ge 2$. Inspired by the Collatz iteration / algorithm ($M=2$), I tried the following function: $$C_M(n) = n/M, \text{ if } n \equiv 0 \mod M, \text{ otherwise } (M+1)n+\{(M-n) \mod M \}$$ We ...
mathoverflowUser's user avatar
9 votes
1 answer
942 views

Residue class sufficiency sets for the Collatz conjecture

I have recently managed to show a sequence of sufficiency sets for the Collatz conjecture whose natural density approaches 0 (the set theoretic limit approaches the set $\{1\}$). It is an extension of ...
Jose Capco's user avatar
  • 2,275
-1 votes
1 answer
376 views

Collatz property implying infinite "fall below" trajectories, is it known?

(this was discovered analyzing Collatz empirically.) a key aspect of resolving Collatz involves looking at the number of iterations for trajectories to "fall below" the initial value. consider a ...
vzn's user avatar
  • 529
5 votes
2 answers
2k views

3n+1 problem and cycles

Just to make sure I am up to date with this problem. I know (or I think I do) that it is not yet proven that there are no non-trivial cycles for the collatz sequence (please correct me if I am wrong). ...
Jose Capco's user avatar
  • 2,275
10 votes
2 answers
4k views

Larger cycle than 4, 2, 1 in Collatz iteration?

(Here I discuss the Collatz problem only for positive integers.) It is possible, by computation, to find all cycles in the Collatz iteration of a fixed length. It is clear that an increase must be ...
DavidLHarden's user avatar
  • 3,645