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A165878
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Number of disconnected 8-regular simple graphs on n vertices.
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8
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 100, 10901, 3470736, 1473822243, 734843169811
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,21
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FORMULA
| a = A180260 - A014378 = Euler_transformation(A014378) - A014378.
a(n) = D(n, 8) in the triangle A068933.
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EXAMPLE
| The a(18)=1 graph is K_9+K_9.
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CROSSREFS
| 8-regular simple graphs: A014378 (connected), this sequence (disconnected), A180260 (not necessarily connected).
Disconnected regular simple graphs: A068932 (any degree), A068933 (triangular array), specified degree k: A157928 (k=0), A157928 (k=1), A165652 (k=2), A165653 (k=3), A033483 (k=4), A165655 (k=5), A165656 (k=6), A165877 (k=7), this sequence (k=8).
Sequence in context: A123616 A001594 A052752 * A175345 A142358 A020477
Adjacent sequences: A165875 A165876 A165877 * A165879 A165880 A165881
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KEYWORD
| nonn,hard,more
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AUTHOR
| Jason Kimberley (Jason.Kimberley(AT)newcastle.edu.au), Sep 29 2009
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