1215 search results - page 91 / 243 » Combinatorics |
150
Voted
COMBINATORICS
1999
15 years 3 months ago
1999
Let k denote the maximum degree of the kth iterated line graph Lk(G). For any connected graph G that is not a path, the inequality k+1 2k - 2 holds. Niepel, Knor, and Solt
108
click to vote
COMBINATORICS
1999
15 years 3 months ago
1999
We show how to count tilings of Aztec diamonds and hexagons with defects using determinants. In several cases these determinants can be evaluated in closed form. In particular, we...
124
Voted
COMBINATORICS
1999
15 years 3 months ago
1999
We prove that the threshold for a random graph to have a k-core is equal to the threshold for having a subgraph which meets a necessary condition of Gallai for being k-critical. 1...
142
click to vote
COMBINATORICS
1999
15 years 3 months ago
1999
We find, in the form of a continued fraction, the generating function for the number of (132)-avoiding permutations that have a given number of (123) patterns, and show how to ext...
COMBINATORICS
1999
15 years 3 months ago
1999
We give an integral identity which was conjectured and proved by using the continuous version of the multi-WZ method. Submitted: May 25, 1999; Accepted: October 20, 1999. Mathemat...