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A046091
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Number of connected planar graphs with n edges.
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9
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1, 1, 1, 3, 5, 12, 30, 79, 227, 709, 2318, 8049, 29372, 112000, 444855, 1833072, 7806724, 34252145, 154342391, 712231465, 3357126655, 16119421175, 78580665333
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listen;
history;
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internal format)
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OFFSET
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0,4
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COMMENTS
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LINKS
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EXAMPLE
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a(3) = 3 since the three connected graphs with three edges are a path, a triangle and a "Y".
The first difference between this sequence and A002905 is for n=9 edges where we see K_{3,3}, the "utility graph".
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PROG
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(nauty)
# count graphs for the sequence by number of vertices v, sum over v afterwards
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CROSSREFS
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KEYWORD
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nonn,nice,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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