A185135 Number of not necessarily connected 3-regular simple graphs on 2n vertices with girth exactly 5.

0, 0, 0, 0, 0, 1, 2, 8, 48, 450, 5752, 90555, 1612917, 31297424, 652159986, 14499787794, 342646826428

Offset

0,7

Links

Table of n, a(n) for n=0..16.

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

Formula

a(n) = A185335(n) - A185336(n).

a(n) = A006925(n) + A185035(n).

Crossrefs

Not necessarily connected 3-regular simple graphs on 2n vertices with girth exactly g: A185130 (triangle); fixed g: A185133 (g=3), A185134 (g=4), this sequence (g=5), A185136 (g=6).

Sequence in context: A052667 A327904 A006925 * A238805 A005867 A280133

Adjacent sequences: A185132 A185133 A185134 * A185136 A185137 A185138

Keyword

nonn,hard,more

Author

Jason Kimberley, Mar 21 2012

Status

approved