[seqfan] Re: No isosceles triangles in a square grid, continued

[Neil Sloane]

and your table exactly matches what I have (which is based on Rob's
calculations,
although you have gone a bit further in some rows
and less far in others)

good to have the confirmation!

Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com


On Wed, Apr 27, 2016 at 4:40 PM, Ron Hardin <rhhardin at att.net> wrote:

> After a few hours with n+k-1 (after which progress will slow or stop):
>
> T(n,k)=Number of nXk 0..1 arrays with exactly n+k-1 having value 1 and no
> three 1s forming an isosceles triangle
> Table starts
> .1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1
> .1.0.1.0.0.0.0.0.0.0.0.0.0.0.0.0..
> .1.1.0.0.0.3.0.2.0.2.0.2.0.2.0....
> .1.0.0.0.0.0.0.0.0.0.0.0.0.0......
> .1.0.0.0.0.0.0.4.0.2.0.0.0........
> .1.0.3.0.0.0.0.0.0.0.1.8..........
> .1.0.0.0.0.0.0.0.0.3..............
> .1.0.2.0.4.0.0.0.1................
> .1.0.0.0.0.0.0.1..................
> .1.0.2.0.2.0.3....................
> .1.0.0.0.0.1......................
> .1.0.2.0.0........................
> .1.0.0.0..........................
> .1.0.2............................
> .1.0..............................
> .1................................
> column 2: 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> column 3: 1 1 0 0 0 3 0 2 0 2 0 2 0 2 0 2 0 2 0 2 0
> column 4: 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> column 5: 1 0 0 0 0 0 0 4 0 2 0 0 0
>  --
> rhhardin at mindspring.com rhhardin at att.net (either)
>
>
>       From: Ron Hardin <rhhardin at att.net>
>  To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
>  Sent: Wednesday, April 27, 2016 12:03 PM
>  Subject: [seqfan] Re: No isosceles triangles in a square grid, continued
>
> Simple to do, yes.  I can't reach far into the diagonal however owing to a
> memory blowup, which stops the antidiagonal search (which is the reason for
> doing columns independently of antidiagonal search).
>  rhhardin at mindspring.com rhhardin at att.net (either)
>
>
>       From: Neil Sloane <njasloane at gmail.com>
>  To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
>  Sent: Wednesday, April 27, 2016 11:48 AM
>  Subject: [seqfan] Re: No isosceles triangles in a square grid, continued
>
> Ron, would it be a simple matter to run
> Tminusone(n,k)=Number of nXk 0..1 arrays with exactly n+k-1 having value 1
> and no three 1s forming an isosceles triangle
> (where I have replaced n+k-2 with n+k-1) ?
>
>
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>