[seqfan] Re: Alternating Vertical and Horizontal Moves In Grid

Giovanni Resta g.resta at iit.cnr.it
Wed Feb 25 20:33:11 CET 2009


Jaume Oliver i Lafont wrote:
> The difference between these sequences starts 0,0,1,0,1,0,1,0...
> so the second bisection of both sequences seems to be the same: 4,14,32,58,92...
> This is not on the EIS, but one half of it appears only once, with a
> simple closed form that makes sense to this problem.
> http://www.research.att.com/~njas/sequences/?q=2,7,16,29,46
>
> Jaume
>   
Well found, but, always under the condition that my program is correct,
I found that for n=12, instead of 121 as in the sequence you linked, I 
got 134,
for the start in the corner, with a nice spiral-like path. The 
computation for the
"start anywhere" is slower, so I do yet not know where it goes, but it 
cannot be smaller
than 134..
I've updated the picture
http://ilex.iit.cnr.it/resta/Leroy2.pdf
to include the cases N=11 and N=12 (in the second page).

giovanni





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