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A137568
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Number of chromatically unique simple graphs on n nodes.
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3
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OFFSET
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1,2
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LINKS
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FORMULA
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PROG
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(Sage)
d = {}
for g in graphs(n):
c = g.chromatic_polynomial()
d[c] = 1 if c not in d else d[c]+1
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CROSSREFS
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Cf. A137567 (number of chromatically non-unique graphs).
Cf. A000088 (number of simple graphs).
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KEYWORD
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nonn,more,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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