On a subset of all the permutations of n marks
Y. L. Varol · The Computer Journal · 1980
A subset of all the permutations of n marks arises naturally in interval exchange transformation problems. Each permutation p1p2 … pn in the set represents a transformation having a dense orbit, and has the properties pi+1≠pi+1 and p1p2 … pi is not a permutation of {1, 2, …, i} for all i, 1≤i≤n−1. A recursive formula is given for the cardinality of this subset, and two algorithms for generating in alphabetic order all the permutations in it are presented.