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A003305
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Figure 8's with 2n edges on the square lattice.
(Formerly M1860)
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0
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2, 8, 40, 208, 1120, 6200, 35236, 204664, 1210392, 7266824, 44184288
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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4,1
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COMMENTS
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Rotations and reflections are distinct. 2n is the total number of edges in the figure. Each "figure 8" is two of the polygons counted by A002931 intersecting at a single point. Like A003304 but now the smaller loop need not be a simple square. - Sean A. Irvine, Mar 21 2017
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REFERENCES
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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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KEYWORD
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nonn,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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