By Manuel Kauers, Christoph Koutschan, and Doron Zeilberger
We hope that Pierre Leroux would have enjoyed this tribute to him. Not only was
he a great "pure" combinatorialist, one of the co-founders of the very abstract
theory of species, he was also very interested in symbolic computation,
and inspired his students to concretize these abstract species by programming them.
While the present article does not talk about species, we are sure that
Pierre would have liked it all the same, especially since it tackles a conjecture
discussed by Richard Stanley, in the problem session that he chaired, back in May 1985,
in the conference so efficiently and warmly organized by him and Gilbert Labelle.
This operator has been added to
TSPP,
as procedure ManueljFree(n,j); . Procedure CheckManueljFree verifies
it empirically for all 1<=j
.pdf
.tex
Pour Pierre Leroux, In Memoriam
Written: Aug. 2, 2008.
Important: This article is accompanied by the following two
Maple packages
Sample Input and Output
Added Aug. 6, 2008:
We have found a j-free operator ,of the form P(N,J,n), where N and J are
the fundamental shift operators in the n and j variables respectively,
annihilating B(n,j) (for the q=1 case).
This is very encouraging, since it indicates that with a bit of more
computation, one should get a j-free operator annihilating
the summand of (Soichi) and (Okada) enabling a fully rigorous proof
in the style of Sister Celine.
maple -q < inMa500 > oMa500
would yield the
output.
Doron Zeilberger's List of Papers