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A185143 Number of not necessarily connected 4-regular simple graphs on n vertices with girth exactly 3. 9
0, 0, 0, 0, 0, 1, 1, 2, 5, 16, 58, 264, 1535, 10755, 87973, 803973, 8020967, 86029760, 983431053, 11913921910, 152352965278, 2050065073002, 28466234288520 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

LINKS

Table of n, a(n) for n=0..22.

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

FORMULA

a(n) = A033301(n) - A185344(n).

a(n) = A184943(n) + A185043(n).

CROSSREFS

Not necessarily connected k-regular simple graphs girth exactly 3: A198313 (any k), A185643 (triangle); fixed k: A026796 (k=2), A185133 (k=3), this sequence (k=4), A185153 (k=5), A185163 (k=6).

Not necessarily connected 4-regular simple graphs with girth exactly g: A185140 (triangle); fixed g: this sequence (g=3), A185144 (g=4).

Sequence in context: A262441 A019448 A243326 * A280760 A000753 A007878

Adjacent sequences:  A185140 A185141 A185142 * A185144 A185145 A185146

KEYWORD

nonn,hard,more

AUTHOR

Jason Kimberley, Mar 12 2012

STATUS

approved

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Last modified February 21 19:26 EST 2018. Contains 299422 sequences. (Running on oeis4.)