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A211179
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Number of free polypentagrams with n cells.
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2
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1, 1, 5, 31, 238, 2020, 17754, 160820, 1479536, 13792972, 129839465
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OFFSET
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1,3
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COMMENTS
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A polypentagram is a plane figure made of five-pointed stars joined edge to edge. Free means that mirror images are counted as the same polypentagram.
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LINKS
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EXAMPLE
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Five different figures can be formed by joining 3 pentagrams, so a(3) = 5.
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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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EXTENSIONS
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STATUS
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approved
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