Permutations by Number of Rises and Successions
نویسنده
چکیده
such that Ijy^j (j=l(l)n) and the latter asks for the number of permutations for which there are a fixed number of j such that lj<lj+i. Two notational conventions will prove useful in what follows. First, it shall be convenient to write the permutation (1.1) as the one line array (h, k, ■ • • , ln) and, secondly, when enumerating permutations by number of rises, we shall attach an initial rise. Thus, for example, the permutations
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