A185136 Number of not necessarily connected 3-regular simple graphs on 2n vertices with girth exactly 6.

0, 0, 0, 0, 0, 0, 0, 1, 1, 5, 32, 385, 7573, 181224, 4624481, 122089999, 3328899592, 93988909792

Offset: 0

Author

Jason Kimberley, Mar 21 2012

Keywords

• nonn
• hard
• more

Links

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

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), A185135 (g=5), this sequence (g=6).

Formula

a(n) = A006926(n) + A185036(n).