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A289987
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Number of unlabeled connected loopless multigraphs with n nodes of degree less than n.
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2
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0, 1, 1, 2, 12, 146, 5847, 716141, 300635753, 430472002801, 2117649544384420, 36154420408979339192, 2165755991529764630384554, 459803603042851200545393118005
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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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Multigraphs are loopless.
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LINKS
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EXAMPLE
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For n=4 the a(4)=12 solutions are:
o--o--o--o o==o--o--o o--o==o--o o==o--o==o
o--o o==o o==o
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o--o o--o o==o
o--o o==o
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|/ |/
o--o o--o
o---o o--o o--o--o
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| x | |/ | o
|/ \| o--o
o---o
(End)
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PROG
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(nauty/bash) for n in {1..8}; do geng -c -D$[${n}-1] ${n} -q | multig -m$[${n}-1] -D$[${n}-1] -u; done
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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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