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A242790
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Number of connected diamond-free graphs on n nodes.
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12
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1, 1, 2, 4, 11, 39, 165, 967, 7684, 87012, 1410465, 32640019
(list;
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internal format)
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OFFSET
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1,3
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COMMENTS
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An equivalent definition: Number of simple connected graphs with n nodes that are have no subgraph isomorphic to the diamond graph or the complete graph K_4. This is the same because a graph contains a diamond as a subgraph iff it contains a diamond or K_4 as induced subgraph. - Falk Hüffner, Jan 11 2015
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LINKS
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Falk Hüffner, tinygraph, software for generating integer sequences based on graph properties, version ece94ef.
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CROSSREFS
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Cf. A077269 (connected squarefree graphs).
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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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a(11) and a(12) added using tinygraph by Falk Hüffner, Jan 15 2016
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STATUS
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approved
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