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

[Ron Hardin]

If I substitute n+k-1 for n+k-2 I get more solutions that I should, according to the thread, if I'm understanding it correctly as about right isosceles triangles.

T(n,k)=Number of nXk 0..1 arrays with exactly n+k-1 having value 1 and no three 1s forming an isosceles right triangle

Table starts
.1.1....1....1.....1.....1.....1.....1.....1.....1......1.....1....1.1.1
.1.0....1....0.....1.....0.....1.....0.....1.....0......1.....0....1.0..
.1.1....0....1.....9.....6....16....66....95...177....493..1153.2238....
.1.0....1....0.....8.....8....71...212...731..1840...5953.18632.........
.1.1....9....8....12....58...367..1952.10854.28952.111036...............
.1.0....6....8....58...192...838..4968.37436............................
.1.1...16...71...367...838..4892.26051..................................
.1.0...66..212..1952..4968.26051........................................
.1.1...95..731.10854.37436..............................................
.1.0..177.1840.28952....................................................
.1.1..493.5953..........................................................
.1.0.1153...............................................................
.1.1....................................................................
.1......................................................................

I'm understanding the thread as saying the exceptions ought to be only

> For (m,n) with 10 >= m >= n >= 2, the only exceptions are
> {(3,2),(6,3),(8,3),(8,5),(9,6),(9,8),(10,3),(10,5),(10,7),(10,9)}, where
> the maximum is instead m + n - 1.

Here's my solutions for (5,2)

..1..1..
..0..0..
..1..1..
..0..0..
..1..1..

and (4,3)

..1..1..1..
..0..0..0..
..0..0..0..
..1..1..1..

Are these valid?  Always possible I'm looking at it wrong.
 rhhardin at mindspring.com rhhardin at att.net (either)