[sage-devel] Re: Catalan Numbers

2009-07-23 Thread Tom Boothby
Cool to hear that people are interested. So far, I've implemented a CatalanCatalog class, which keeps lists of descriptions of Catalan constructions, maps between different constructions, and functions which enumerate various families of constructions. It also maintains a directed graph of which

[sage-devel] Re: Catalan Numbers

2009-07-23 Thread Franco Saliola
On Thu, Jul 23, 2009 at 8:20 AM, Tom Boothby wrote: > Richard Stanley currently lists 172 combinatorial interpretations of > the Catalan numbers.  I've been doing some research on Coxeter groups > this summer, and we recently found that a class of permutations in S_n > which are counted by the Cat

[sage-devel] Re: Catalan Numbers

2009-07-23 Thread Dan Drake
On Wed, 22 Jul 2009 at 11:20PM -0700, Tom Boothby wrote: [...] > I'm mostly doing this for research and for pleasure, but since I'm > doing the research with a few partners, the code is readable. I'm > wondering: is there sufficient interest for this to be added to Sage? > If I manage to construct

[sage-devel] Re: Catalan Numbers

2009-07-23 Thread Marshall Hampton
You could make the ultimate "proof-without-words" submission! I think this is cool, and although I am not a combinatorics person at all it seems reasonable as an addition to sage. I think it could underpin a really fantastic @interact. -Marshall On Jul 23, 1:20 am, Tom Boothby wrote: > Richar