1215 search results - page 126 / 243 » Combinatorics |
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COMBINATORICS
2000
15 years 6 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...
161
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COMBINATORICS
2000
15 years 6 months ago
2000
In this paper we consider the problem of establishing a value r0 such that almost all random graphs with n vertices and rn edges, r > r0, are asymptotically not 3-colorable. In...
169
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COMBINATORICS
2000
15 years 6 months ago
2000
In a previous paper it was established that there are at least 27 non-isomorphic strongly regular (40, 12, 2, 4) graphs. Using a different and more efficient method we have re-inv...
169
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COMBINATORICS
2000
15 years 6 months ago
2000
We prove a conjecture of Cohn and Propp, which refines a conjecture of Bosley and Fidkowski about the symmetry of the set of alternating sign matrices (ASMs). We examine data aris...
121
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COMBINATORICS
2002
15 years 6 months ago
2002
A fork stack is a generalised stack which allows pushes and pops of several items at a time. We consider the problem of determining which input streams can be sorted using a singl...