2 search results - page 1 / 1 » Permutations Which Avoid 1243 and 2143, Continued Fractions,... |
COMBINATORICS
2002
13 years 4 months ago
2002
Several authors have examined connections between permutations which avoid 132, continued fractions, and Chebyshev polynomials of the second kind. In this paper we prove analogues...
COMBINATORICS
2000
13 years 4 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...