A198318 Number of, not necessarily connected, regular simple graphs on n vertices with girth exactly 8.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 6, 5, 7, 7, 10, 10, 15, 13, 29, 17, 176, 23, 4364, 30, 266398, 39, 20807734, 51

Offset

0,25

Links

Table of n, a(n) for n=0..47.

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

Formula

a(n) = A186748(n) + A210718(n).

a(n) = A185318(n) - A185319(n).

Crossrefs

Not necessarily connected regular simple graphs girth exactly g: A198313 (g=3), A198314 (g=4), A198315 (g=5), A198316 (g=6), A198317 (g=7), this sequence (g=8).

Sequence in context: A083802 A325691 A326668 * A100881 A053263 A317908

Adjacent sequences: A198315 A198316 A198317 * A198319 A198320 A198321

Keyword

nonn,more,hard

Author

Jason Kimberley, Dec 19 2012

Status

approved