A186727 Number of connected regular graphs with n nodes and girth at least 7.

1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 4, 1, 22, 1, 547, 1, 30369, 1, 1782841, 1, 95079084, 1, 4686063121, 1

Offset

0,25

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..39.

Jason Kimberley, Index of sequences counting connected k-regular simple graphs with girth at least g

Jason Kimberley, Connected regular graphs with girth at least 7

M. Meringer, Tables of Regular Graphs

Formula

a(n) = sum of the n-th row of A186717.

Crossrefs

Connected regular graphs of any degree with girth at least g: A005177 (g=3), A186724 (g=4), A186725 (g=5), A186726 (g=6), this sequence (g=7), A186728 (g=8), A186729 (g=9).

Connected k-regular simple graphs with girth at least 7: this sequence (any k), A186717 (triangle); specific k: A185117 (k=2), A014375 (k=3).

Sequence in context: A092891 A229484 A080212 * A145998 A218952 A177413

Adjacent sequences: A186724 A186725 A186726 * A186728 A186729 A186730

Keyword

nonn,more,hard

Author

Jason Kimberley, Nov 25 2011

Status

approved