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A057724
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Number of "polyares" of order n (turning over allowed).
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2
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1, 3, 9, 42, 180, 889, 4392, 22432, 115469, 602112, 3161949, 16723643, 88933764, 475286752, 2550780323
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OFFSET
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1,2
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COMMENTS
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An n-are is a shape formed from an n-celled polyomino by removing half of each cell such that edge connections are not broken.
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REFERENCES
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Enumeration attributed by Andrew Clarke to Brendan Owen.
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LINKS
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Eric Weisstein's World of Mathematics, Polyare
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CROSSREFS
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KEYWORD
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nonn,nice,more
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AUTHOR
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EXTENSIONS
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Corrected a(8) and added a(12)-a(15) by John Mason, Mar 19 2023
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STATUS
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approved
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