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URL: https://oeis.org/A210717

⇱ A210717 - OEIS

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A210717

Number of disconnected regular simple graphs on n vertices with girth exactly 7.

1

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 6, 7, 8, 10, 11, 13, 15, 18, 20, 24, 27, 32, 36, 42, 48, 56, 63, 73, 83, 96, 109, 125, 144, 162, 210, 209, 845, 270, 32541, 346, 1885800, 443, 101215159, 565, 5025321572

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,22

LINKS

Table of n, a(n) for n=0..62.

Jason Kimberley, Index of sequences counting disconnected k-regular simple graphs with girth exactly g

FORMULA

a(n) = A185217(n) - A185218(n).

CROSSREFS

Sequence in context: A025150 A026800 A185327 * A171962 A238208 A350892

Adjacent sequences: A210714 A210715 A210716 * A210718 A210719 A210720

KEYWORD

nonn,more,hard

AUTHOR

Jason Kimberley, Dec 18 2012

STATUS

approved