A185264 Number of disconnected 6-regular simple graphs on n vertices with girth at least 4.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 10, 7, 277, 3742, 483330, 69827771, 14836620025

Offset

0,29

Links

Table of n, a(n) for n=0..34.

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

Formula

a(n)

= A185364(n) - A058276(n)

= Euler_transformation(A058276)(n) - A058276(n).

Crossrefs

6-regular simple graphs with girth at least 4: A058276 (connected), this sequence (disconnected), A185364 (not necessarily connected).

Disconnected k-regular simple graphs with girth at least 4: A185214 (any k), A185204 (triangle); specified degree k: A185224 (k=2), A185234 (k=3), A185244 (k=4), A185254 (k=5), this sequence (k=6), A185274 (k=7), A185284 (k=8), A185294 (k=9).

Sequence in context: A210283 A227473 A038309 * A128357 A024134 A180197

Adjacent sequences: A185261 A185262 A185263 * A185265 A185266 A185267

Keyword

nonn,more,hard

Author

Jason Kimberley, Feb 22 2011

Status

approved