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A185043 Number of disconnected 4-regular simple graphs on n vertices with girth exactly 3. 8
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 3, 8, 25, 88, 377, 2026, 13349, 104593, 930571, 9124627, 96699740, 1095467916, 13175254799, 167460501260, 2241576473025, 31510509517563, 464047467911837, 7143984462730072, 114749034352969037, 1919656978492976231 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,13

LINKS

Table of n, a(n) for n=0..31.

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

FORMULA

a(n) = A033483(n) - A185244(n).

CROSSREFS

4-regular simple graphs with girth exactly 3: A184943 (connected), this sequence (disconnected), A185143 (not necessarily connected).

Disconnected k-regular simple graphs with girth exactly 3: A210713 (any k), A210703 (triangle); for fixed k: A185033 (k=3), this sequence (k=4), A185053 (k=5), A185063 (k=6).

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

Sequence in context: A148800 A244278 A190343 * A033483 A130522 A006219

Adjacent sequences:  A185040 A185041 A185042 * A185044 A185045 A185046

KEYWORD

nonn,hard

AUTHOR

Jason Kimberley, Feb 29 2012

EXTENSIONS

Terms a(27)-a(31), due to the extension of A006820 by Andrew Howroyd, from Jason Kimberley, Mar 16 2020

STATUS

approved

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Last modified September 24 07:28 EDT 2020. Contains 337317 sequences. (Running on oeis4.)