[seqfan] Re: Brick sequences

[franktaw at netscape.net]

-----Original Message-----
From: Mitch Harris <maharri at gmail.com>

>So is the following pattern allowed? :
>
> =     =
>= = = = =

Yes, absolutely.  This is where my sequence differs from A001524, which 
does not allow it.

>If so, then these might be counted by generalized Catalan #'s.
>
>(paths from 0,0 to n,n below  x=y, with steps (0,1), (1,0), (1,1) ?)
>
>Google for
>
>  Snevily West bricklaying problem

I was able to download the paper from 
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.52.7065

This is closely related, but counts the number of bricks in the bottom 
row instead of the number of bricks in the entire stack.  I'm still 
looking at it to see if it can be made relevant to my problem.

>There is mention of this paper once in the OEIS, but in a seemingly
>unrelated sequence.
>The bricklaying problem seems recent enough that it's not mentioned in
>Stanley.
>
>Mitch Harris

Franklin T. Adams-Watters