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A045310
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Number of matchings in n-cube.
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5
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OFFSET
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0,2
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COMMENTS
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Equivalently, the number of decompositions of an n-dimensional cube of size 2 into (zero or more) unit cubes (1 X 1 X ... X 1) and "dominoes" (2 X 1 X 1 X ... X 1). - Hugo van der Sanden, Nov 30 2016
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LINKS
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Per Hakan Lundow, GrafPack (Mathematica package).
Eric Weisstein's World of Mathematics, Matching
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EXAMPLE
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E.g., for n=2, we have
1 matching of size 0 (i.e., the empty matching)
4 matchings of size 1 (i.e., an edge)
2 matchings of size 2 (that are the perfect matchings).
So a(2) = 1 + 4 + 2 = 7, whereas A005271(2) = 2. (End)
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PROG
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(Perl) # See Links section.
(C) /* See Links section. */
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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STATUS
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approved
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