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A093427
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Number of different two-dimensional burst patterns in the grid graph with eight neighbors.
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2
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OFFSET
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1,2
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COMMENTS
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The grid graph with eight neighbors has Z^2 as vertices and each vertex (x,y) is connected to (x-1,y),(x+1,y),(x,y-1),(x,y+1),(x-1,y-1),(x+1,y+1),(x-1,y+1),(x+1,y-1). A cluster of size t is a set of t points such that each pair of points of the set is on a connected path contained entirely within the set. A burst pattern is a labeling of Z^2 with 0's and 1's. The term a(n) denotes the number of different (up to a translation) burst patterns whose 1's are covered by a cluster of size n.
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LINKS
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EXAMPLE
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a(2) = 5 because we have the following burst patterns (the *'s mark the 1's):
1) *
2) **
3) *
...*
4) .*
...*
5) *
....*
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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Tuvi Etzion and Moshe Schwartz (etzion(AT)cs.technion.ac.il), May 11 2004
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STATUS
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approved
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