A185246 Number of disconnected 4-regular simple graphs on n vertices with girth at least 6.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 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, 0, 5, 0, 23, 0, 1301, 25, 495379, 13529

Offset

0,57

Links

Table of n, a(n) for n=0..63.

Jason Kimberley, Disconnected regular graphs with girth at least 6

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

Formula

a(n) = A185346(n) - A058348(n) = Euler_transformation(A058348)(n) - A058348(n).

Crossrefs

4-regular simple graphs with girth at least 4: A058348 (connected), this sequence (disconnected), A185346 (not necessarily connected).

Disconnected 4-regular simple graphs with girth at least g: A033483 (g=3), A185244 (g=4), A185245 (g=5), this sequence (g=6).

Disconnected k-regular simple graphs with girth at least 6: A185216 (all k), A185206 (triangle); A185226 (k=2), A185236 (k=3), this sequence (k=4).

Sequence in context: A284177 A222755 A279500 * A279547 A279700 A279603

Adjacent sequences: A185243 A185244 A185245 * A185247 A185248 A185249

Keyword

nonn,more,hard

Author

Jason Kimberley, Feb 22 2011

Status

approved