[seqfan] Re: Knight's tour on infinite board

[Hugo Pfoertner]

I have added a drawing to A068610. I've tried to decipher the code in the
Mma notebook, but the method seems to be table driven. Someone with
Mathematica might be more successful.

On Sat, May 4, 2019 at 6:14 PM Hans Havermann <gladhobo at bell.net> wrote:

> HP: "it seems highly likely that indeed Jay Warendorff's demo was used
> together with the 8 possible initial steps to create the 8 sequences"
>
> The demo dates to 2011. Frank Ellermann's link was added in 2012 but it
> should be noted that Ellermann's contribution is dated 2002, only 12 days
> after Secelle & Heeffer's date of authorship.
>
> I can now verify (done by hand) that the 60 terms (do we really need the
> offset to be zero?) of A068610 correspond to Warendorff's demo. It is
> dependant of course on the Ellermann spiral numbering scheme. The tour
> starts by filling in a central 5-by-5 square, starting in the square's
> center and ending in its SE corner. It then jumps 2 south and 1 east and
> proceeds to circle the 5-by-5 square clockwise four times filling in the
> now-9-by-9 square and ending in its SE corner. And so on.
>
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