A210715 - OEIS

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A210715

Number of disconnected regular simple graphs on n vertices with girth exactly 5.

1

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 6, 9, 9, 22, 13, 82, 18, 618, 26, 7164, 36, 107862, 50, 1876730, 70, 35924810, 95, 741405213, 131, 16356067216, 323, 383931367731, 132977

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,16

LINKS

Table of n, a(n) for n=0..43.

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

FORMULA

a(n) = A185215(n) - A185216(n).

CROSSREFS

Sequence in context: A078935 A276774 A129768 * A072926 A080087 A345163

Adjacent sequences: A210712 A210713 A210714 * A210716 A210717 A210718

KEYWORD

nonn,more,hard

AUTHOR

Jason Kimberley, Dec 10 2012

STATUS

approved