Combinatorial proof of the log-convexity for the derangements in the Coxeter groups

Hiranya Kishore Dey, Subhajit Ghosh

We provide the combinatorial proofs of the log-convexity for the derangement numbers in the symmetric group ${\mathfrak{S}}_n$, hyperoctahedral group ${\mathfrak{B}}_n$, and the demihy…