Congruent Products Under XOR; Fibbinary Numbers
Paul D. Hanna
pauldhanna at juno.com
Tue Jan 24 02:19:43 CET 2006
Dean (and Seqfans),
Thanks for catching my mistake.
It seems obvious (now) that the conjecture is false - in fact,
there are so many exceptions I wonder how I missed them.
A better conjecture may be:
there exists an infinite set of integers n that satisfy
p*n XOR q*n = (p XOR q)*n for all positive integers p,q, r.
I find no exceptions to this guess.
Yet my focus was primarily on what different values of {p,q,r}
define the same sequence that satisfies p*n XOR q*n = r*n
when GCD(p,q) is odd. This remains a mystery to me.
Perhaps Ralf Stephan's comment offers a clue;
the binary mask, such as ((0)*0001)*(0*) that match A048718(n),
may determine which {p, q, r} define equivalent sequences.
Thanks,
Paul
> > As a generalization, consider the sequences defined by:
> > "Numbers n such that: p*n XOR q*n = r*n." for positive integers
> p, q, r.
> >
> > Q: For what p, q, r, does the above definition generate sequences
> not {0}?
> > A: Iff r = p XOR q (conjecture).
> >
> > Can anyone prove this conjecture?
>
> It's not true. Let p=2, q=3, and r=5. Then n=3 is in the
> sequence,
> since 2*3 XOR 3*3 = 6 XOR 9 = 15 = 5*3. But 2 XOR 3 = 1, not 5.
>
> Dean Hickerson
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