Geodesic
Permutabilitäten kleiner endlicher Gruppen
Séminaire lotharingien de combinatoire, Tome 19 (1988) 
Volkmar Welker. Permutabilitäten kleiner endlicher Gruppen. Séminaire lotharingien de combinatoire, Tome 19 (1988). http://geodesic.mathdoc.fr/item/SLC_1988_19_a18/
@article{SLC_1988_19_a18,
     author = {Volkmar Welker},
     title = {Permutabilit\"aten kleiner endlicher {Gruppen}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1988},
     volume = {19},
     url = {http://geodesic.mathdoc.fr/item/SLC_1988_19_a18/}
}
TY  - JOUR
AU  - Volkmar Welker
TI  - Permutabilitäten kleiner endlicher Gruppen
JO  - Séminaire lotharingien de combinatoire
PY  - 1988
VL  - 19
UR  - http://geodesic.mathdoc.fr/item/SLC_1988_19_a18/
ID  - SLC_1988_19_a18
ER  - 
%0 Journal Article
%A Volkmar Welker
%T Permutabilitäten kleiner endlicher Gruppen
%J Séminaire lotharingien de combinatoire
%D 1988
%V 19
%U http://geodesic.mathdoc.fr/item/SLC_1988_19_a18/
%F SLC_1988_19_a18

Voir la notice de l'acte provenant de la source Séminaire Lotharingien de Combinatoire website

Given a group G, let P(n) be the property that for all x1,...,xn in G there exists a product of these elements in a permuted order which is equal to (the non-permuted poduct) x1...xn. Now defined P(G) to be the minimal n for which G possesses the property P(n) but not P(n-1). We present results on the (highly non-trivial) computation of P(G), in particular for groups G of order up to 20.