[seqfan] Re: A possible characterization of A125121

William Keith william.keith at gmail.com
Sun Nov 17 18:01:52 CET 2013

On Sat, Nov 16, 2013 at 6:22 PM, Allan Wechsler <acwacw at gmail.com> wrote:

> I think I am having a terminology difference with David Wilson. I intended
> my "tilings" to cover all the integers, not just the non-negative ones, and
> thus right shifts are not only allowed, they are necessary.
> This also explains our difference of opinion about 35.  I agree 100011
> can't tile just the non-negative integers, but it *can* tile all the
> integers, as I thought I showed in a previous message.

More importantly, don't you also need flips, which don't correspond to

0100011 would collide

10101111 but now what do you do about those two single 0s?  You can cover
them if you take

111111111111 and now you can tile the integers.

But reversal is not a simple arithmetic operation.

William Keith

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