Counting of even and odd restricted permutations
Vladimir Baltić, Dragan Stevanović · Ars Mathematica Contemporanea · 2015
Let p be a permutation of the set N n = {1, 2, …, n } . We introduce techniques for counting N ( n ; k ; r ; I ; π ) , the number of even or odd restricted permutations of N n satisfying the conditions − k ≤ p ( i ) − i ≤ r (for arbitrary natural numbers k and r ) and p ( i ) − i ∉ I (for some set I ) and π = 0 for even permutations and π = 1 for odd permutations.