[seqfan] Re: Correcting A002932 (n-step walks on square lattice)

Joseph S. Myers jsm at polyomino.org.uk
Mon Nov 22 17:16:09 CET 2010


Unfortunately I don't think I'm licensed to redistribute the article 
electronically.  But I don't see any sign of the lattice being bounded.  
The article describes quite a complicated method of calculating the terms 
(starting from recurrences for paths where only local self-intersections / 
nearest-neighbour contacts are forbidden, then subtracting terms for when 
these occur at a greater distance along the path) which could well be 
error-prone for higher-order terms.

-- 
Joseph S. Myers
jsm at polyomino.org.uk

On Mon, 22 Nov 2010, Christopher Gribble  wrote:

> Joseph,
> 
> I have been working with Tom Young on a set of related problems for some
> time.  I would be most grateful if you could send me a copy of the Fisher
> and Hiley reference as I do not have access to it.  I think that the title
> of A002932 may need to be made more explicit, since it does not state
> whether the lattice is bounded or not, and, if so, what form the boundary
> takes. Of course, no restriction on path construction is mentioned either.
> I have calculated many cases for the general bounded lattice problem with
> the restriction you describe.  Perhaps we can compare notes.
> 
> Best regards,
> Chris Gribble




More information about the SeqFan mailing list