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URL: https://oeis.org/A084270

⇱ A084270 - OEIS

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A084270
Number of labeled 2-chromatic (i.e., chromatic number = 2) graphs on n nodes.
3
0, 1, 6, 40, 375, 5176, 103236, 2922445, 116011230, 6433447396, 498234407451, 54007795331920, 8213123246906760, 1756336596363006841, 528975889250504033526, 224688018516023267969440, 134708289561117007261966815
OFFSET
1,3
LINKS
Eric Weisstein's World of Mathematics, n-Chromatic Graph
FORMULA
a(n) = A047864(n)-1. - Vladeta Jovovic, Jul 31 2003
CROSSREFS
Sequence in context: A000683 A352357 A143342 * A284195 A053677 A204563
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, May 24 2003
EXTENSIONS
More terms from Vladeta Jovovic, Jul 31 2003
One further term from David Wasserman, Dec 13 2004
STATUS
approved