

A006855


Maximal edges in nnode 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
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OFFSET

1,3


REFERENCES

M. Aigner and G. M. Ziegler, Proofs from The Book, SpringerVerlag, Berlin, 1999. Chap. 20 gives a simple proof of the upper bound (n/4)(1+sqrt(4n3)) and of the fact that it is asymptotically good.  Chris Thompson, Aug 14 2001
Zoltan Füredi, <a href="http://www.math.uiuc.edu/~zfuredi/PUBS/furedi_C4abs.pdf">Quadrilateralfree graphs with maximum number of edges</a>, Extended abstract, Proceedings of the Japan Workshop on Graph Th. and Combinatorics, University, Yokohama, Japan 1994, pp. 1322 (see Section 6).
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.


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



