A185034 Number of disconnected 3-regular simple graphs on 2n vertices with girth exactly 4.

0, 0, 0, 0, 0, 0, 1, 2, 9, 35, 176, 1151, 10329, 120456, 1701834, 27500216, 492269472, 9599036308, 201954501535, 4555108534562

Offset

0,8

Links

Table of n, a(n) for n=0..19.

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

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

Formula

a(n) = A185234(n) - A185235(n).

Crossrefs

Disconnected k-regular simple graphs with girth exactly 4: this sequence (k=3), A185044 (k=4).

Disconnected 3-regular simple graphs with girth exactly g: A185033 (g=3), this sequence (g=4), A185035 (g=5), A185036 (g=6), A185037 (g=7).

Sequence in context: A150964 A150965 A150966 * A185234 A357202 A306791

Adjacent sequences: A185031 A185032 A185033 * A185035 A185036 A185037

Keyword

nonn,more,hard

Author

Jason Kimberley, Feb 29 2012

Status

approved