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A005643

Number of labeled irreducible 2-connected graphs with n edges.

1, 26, 1858, 236856, 53458832, 21494404400, 15580475076986, 20666605559464968, 50987322515860980236, 237747564913232367202656, 2125708395579372100915553094

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OFFSET

4,2

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=4..14.

T. R. S. Walsh, Counting labeled three-connected and homeomorphically irreducible two-connected graphs, J. Combin. Theory Ser. B 32 (1982), no. 1, 1-11.

CROSSREFS

Cf. A054597.

Sequence in context: A123537 A220503 A054597 * A054853 A257947 A245929

Adjacent sequences: A005640 A005641 A005642 * A005644 A005645 A005646

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

STATUS

approved

URL: https://oeis.org/A005643

⇱ A005643 - OEIS