[seqfan] Re: interesting idea, weird ramifications, as yet unsolved

Luca Petrone luca.petrone at libero.it
Tue Jun 9 07:20:09 CEST 2020


Of course there are "easy" formulas to calculate how many elements of X_N have, for example, k repetition of one element, but things get non-sensely complicated of you are asking k repetions of one item, l repetitions of another item and so on: is really this the question? and what is it the meaning of it?
Best Regards,
Luca
> Il 7 giugno 2020 alle 20.16 Wouter Meeussen <wouter.meeussen at telenet.be> ha scritto:
> 
> 
> “Pairwise combinations of distinct elements”
> see https://math.stackexchange.com/questions/3708151
> 
> my feeling is that Algebraic Combinatorics should clarify this, reducing it to a well known pattern.
> I tried but failed dismally.
> 
> It boils down to a list of monomials X_(k+1) generated by
> 
> (X_k ** X_k  - X_k . X_k )/2 where “**” represents the outer product.
> 
> The author (‘Cesare’) only asks for a very limited property of these multinomials, but there is a lot of other ‘enumerative combinatorics’ going on here.
> 
> Does anyone recognise the patten?
> 
> Wouter.
> 
> --
> Seqfan Mailing list - http://list.seqfan.eu/


More information about the SeqFan mailing list