[seqfan] Re: Barry Cipra article in Science

Joerg Arndt arndt at jjj.de
Sun Feb 28 12:23:02 CET 2010

* Artur <grafix at csl.pl> [Feb 28. 2010 09:56]:
> Dear Seqfans,
> I was read with attention article about "toothpick sequence" A139250.
> I was find that few analogical sequences can be constructed in 3 D space 
> (where inspite line of length 2 will be square 2 x 2 added to the each 
> free corners)
> If we take one of the possible variant that projection from the 3 D 
> space on the observer plane will be that same as drawing in Barry Cipra 
> article
> This sequence will be bieginning:
> 0,1,5,9,25,...

Not sure the additions are 'forced' by definition.
That is, there may be more than one way to add new squares.

> and first difference (number of moves in each step of drawing) will be 
> (analogon of A160409)
> 0,1,4,4,16,....
> Who is able find more terms in mathematical construction?

Rather use a computer!

> Best wishes
> Artur

cheers,    jj

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