The Eulerian distribution on centrosymmetric involutions

Marilena Barnabei (1) , Flavio Bonetti (1) , Matteo Silimbani (1)

1 Department of Mathematics [Bologna]

We present an extensive study of the Eulerian distribution on the set of centrosymmetric involutions, namely, involutions in S(n) satisfying the property sigma(i) + sigma(n + 1 - i) = n + 1 for every i = 1 ... n. We find some combinatorial properties for the generating polynomial of such distribution, together with an explicit formula for its coefficients. Afterwards, we carry out an analogous study for the subset of centrosymmetric involutions without fixed points.

Domaines: Mathématique discrète [cs.DM]

Marilena Barnabei, Flavio Bonetti, Matteo Silimbani. The Eulerian distribution on centrosymmetric involutions. Discrete Mathematics and Theoretical Computer Science, 2009, Vol. 11 no. 1 (1), pp.95--115. ⟨10.46298/dmtcs.469⟩. ⟨hal-00988181⟩