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A165628
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Number of 7-regular graphs (septic graphs) on 2n vertices.
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11
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1, 0, 0, 0, 1, 5, 1547, 21609301, 733351105935, 42700033549946255, 4073194598236125134140, 613969628444792223023625238, 141515621596238755267618266465449
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OFFSET
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0,6
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COMMENTS
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Because the triangle A051031 is symmetric, a(n) is also the number of (2n-8)-regular graphs on 2n vertices.
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LINKS
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FORMULA
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MATHEMATICA
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A014377 = Cases[Import["https://oeis.org/A014377/b014377.txt", "Table"], {_, _}][[All, 2]];
(* EulerTransform is defined in A005195 *)
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CROSSREFS
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7-regular simple graphs: A014377 (connected), A165877 (disconnected), this sequence (not necessarily connected).
Regular graphs A005176 (any degree), A051031 (triangular array), chosen degrees: A000012 (k=0), A059841 (k=1), A008483 (k=2), A005638 (k=3), A033301 (k=4), A165626 (k=5), A165627 (k=6), this sequence (k=7), A180260 (k=8).
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KEYWORD
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nonn,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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