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A006856 Maximal number of edges in n-node graph of girth at least 5.
(Formerly M0624)
2
0, 1, 2, 3, 5, 6, 8, 10, 12, 15, 16, 18, 21, 23, 26, 28, 31, 34, 38, 41, 44, 47, 50, 54, 57, 61, 65, 68, 72, 76, 80, 85 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

Brendan McKay, personal communication.

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=1..32.

J Backelin, Sizes of the extremal girth 5 graphs of orders from 40 to 49, arXiv preprint arXiv:1511.08128, 2015

Michael Codish, Alice Miller, Patrick Prosser, Peter J. Stuckey, Breaking Symmetries in Graph Representation, IJCAI 2013

David K. Garnick, Y. H. Harris Kwong and Felix Lazebnik, Extremal Graphs without Three-Cycles or Four-Cycles, Journal of Graph Theory, 17 (1993), 633-645.

Alice Miller and Michael Codish, Graphs with girth at least 5 with orders between 20 and 32, arXiv:1708.06576 [math.CO], 2017.

CROSSREFS

Cf. A159847.

Sequence in context: A011864 A045919 A224955 * A249013 A211964 A140199

Adjacent sequences:  A006853 A006854 A006855 * A006857 A006858 A006859

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane

EXTENSIONS

Two more terms from David Garnick (dgarnick(AT)gmail.com), Jan 09 2007

Two more terms from Michael Codish, Apr 07 2013

Definition clarified by Jörgen Backelin, Jun 18 2015

STATUS

approved

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Last modified February 21 22:56 EST 2018. Contains 299427 sequences. (Running on oeis4.)