Séminaire Lotharingien de Combinatoire, B08b (1984), 6 pp.
[Formerly: Publ. I.R.M.A. Strasbourg, 1984, 229/S-08, p. 11-16.]

Jacques Désarménien

Une autre interprétation du nombre des dérangements

Abstract. Another class of permutations in a one-to-one correspondence with the derangements is introduced that provides a natural interpretation of the usual recurrence: d(n)=nd(n-1)+1 (n even) and d(n)=nd(n-1)-1 (n odd). Those permutations are exactly those whose Lehmer codings start with an even number of 1's.

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