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A165626 Number of 5-regular graphs (quintic graphs) on 2n vertices. 12
1, 0, 0, 1, 3, 60, 7849, 3459386, 2585136741, 2807105258926 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Because the triangle A051031 is symmetric, a(n) is also the number of (2n-6)-regular graphs on 2n vertices.

REFERENCES

M. Meringer, Fast Generation of Regular Graphs and Construction of Cages. Journal of Graph Theory, 30 (1999), 137-146.

LINKS

Table of n, a(n) for n=0..9.

Jason Kimberley, Index of sequences counting not necessarily connected k-regular simple graphs with girth at least g

M. Meringer, Tables of Regular Graphs

N. J. A. Sloane, Transforms

FORMULA

Euler transformation of A006821.

CROSSREFS

5-regular simple graphs: A006821 (connected), A165655 (disconnected), this sequence (not necessarily connected).

Regular graphs A005176 (any degree), A051031 (triangular array), specified degrees: A000012 (k=0), A059841 (k=1), A008483 (k=2), A005638 (k=3), A033301 (k=4), this sequence (k=5), A165627 (k=6), A165628 (k=7), A180260 (k=8).

Sequence in context: A036770 A201699 A006821 * A120307 A022915 A093883

Adjacent sequences:  A165623 A165624 A165625 * A165627 A165628 A165629

KEYWORD

nonn,hard,more

AUTHOR

Jason Kimberley, Sep 22 2009

EXTENSIONS

Regular graphs cross-references edited by the author, Nov 07 2009

a(9) from the author, Nov 24 2009

STATUS

approved

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Last modified October 16 12:35 EDT 2018. Contains 316263 sequences. (Running on oeis4.)