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A186724
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Number of connected regular graphs with n nodes and girth at least 4.
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19
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1, 1, 1, 0, 1, 1, 2, 1, 4, 1, 10, 3, 37, 32, 340, 1608, 18020, 193907, 2867725, 32674058, 1581632114, 6705889824
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,7
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LINKS
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FORMULA
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a(n) = sum of the n-th row of A186714.
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CROSSREFS
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Regular graphs, of any degree, with girth at least 4: this sequence (connected), A185214 (disconnected), A185314 (not necessarily connected).
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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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