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A174313
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Number of n-step walks on hexagonal lattice (no points repeated, no adjacent points unless consecutive in path).
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6
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1, 6, 18, 54, 162, 474, 1398, 4074, 11898, 34554, 100302, 290322, 839382, 2422626, 6984342, 20110806, 57851358, 166258242, 477419658, 1369878582, 3927963138, 11255743434, 32235116502, 92267490414, 263968559874, 754837708494, 2157584748150, 6164626128066, 17606866229010
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OFFSET
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0,2
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COMMENTS
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The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.
Fisher and Hiley give 290334 and 839466 as their last terms instead of 290322 and 839382 (see A002933). Douglas McNeil confirms the correction on the seqfan list Nov 27 2010.
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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CROSSREFS
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Cf. A173380 for square lattice equivalent.
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KEYWORD
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nonn,walk
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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