3 search results - page 1 / 1 » Restricted even permutations and Chebyshev polynomials |
DM
2006
13 years 7 months ago
2006
We study generating functions for the number of even (odd) permutations on n letters avoiding 132 and an arbitrary permutation on k letters, or containing exactly once. In sever...
DM
2007
13 years 7 months ago
2007
Several authors have examined connections between restricted permutations and Chebyshev polynomials of the second kind. In this paper we prove analogues of these results for color...
COMBINATORICS
2000
13 years 7 months ago
2000
Let fr n(k) be the number of 132-avoiding permutations on n letters that contain exactly r occurrences of 12 . . . k, and let Fr(x; k) and F (x, y; k) be the generating functions d...