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A006855 Maximal edges in n-node squarefree graph.
(Formerly M2320)
0
0, 1, 3, 4, 6, 7, 9, 11, 13, 16, 18, 21, 24, 27, 30, 33, 36, 39, 42, 46, 50, 52, 56, 59, 63, 67, 71, 76, 80, 85, 90 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

M. Aigner and G. M. Ziegler, Proofs from The Book, Springer-Verlag, Berlin, 1999. Chap. 20 gives a simple proof of the upper bound (n/4)(1+sqrt(4n-3)) and of the fact that it is asymptotically good. - Christopher E. Thompson, Aug 14 2001

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..31.

Zoltan F├╝redi, Quadrilateral-free graphs with maximum number of edges, Extended abstract, Proceedings of the Japan Workshop on Graph Th. and Combinatorics, University, Yokohama, Japan 1994, pp. 13-22 (see Section 6).

CROSSREFS

Sequence in context: A247425 A236444 A244239 * A229173 A066499 A201471

Adjacent sequences:  A006852 A006853 A006854 * A006856 A006857 A006858

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(23)-a(31) from Michel Marcus, Jul 23 2014

STATUS

approved

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Last modified September 2 10:52 EDT 2015. Contains 261279 sequences.