A007008 - OEIS

A007008

Chvatal conjecture for radius of graph of maximal intersecting sets.
(Formerly M2484)

0, 1, 1, 3, 5, 11, 22, 47, 93, 193, 386, 793, 1586, 3238, 6476, 13167, 26333, 53381, 106762, 215955, 431910, 872218, 1744436, 3518265, 7036530, 14177066, 28354132, 57079714, 114159428, 229656076, 459312152, 923471727, 1846943453, 3711565741, 7423131482

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OFFSET

1,4

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=1..35.

Jan C. Bioch and Toshihide Ibaraki, Generating and approximating nondominated coteries, IEEE Transactions on parallel and distributed systems 6 (1995), 905-914.

D. E. Loeb and A. Meyerowitz, The maximal intersecting family of sets graph, in H. Barcelo and G. Kalai, editors, Proceedings of the Conference on Jerusalem Combinatorics 1993. AMS series Contemporary Mathematics, 1994. [broken link]

A. Meyerowitz, Maximal intersecting families, European J. Combin. 16 (1995), no. 5, 491-501.

FORMULA

It is conjectured that a(2n+1)=A000346(n-1) for n>0. - Ralf Stephan, May 03 2004

a(n) = round(2^(n-2)-binomial(n-1,floor((n-1)/2))/2), cf. Thm. 14 in the Loeb-Meyerowitz paper. - M. F. Hasler, Jan 14 2014

PROG

(PARI) A007008(n)=2^n\4-binomial(n-1, (n-1)\2)\2 \\ - M. F. Hasler, Jan 14 2014

CROSSREFS

Cf. A000346, A007007, A001206.

Sequence in context: A391600 A394221 A005830 * A018110 A227806 A262431

Adjacent sequences: A007005 A007006 A007007 * A007009 A007010 A007011

KEYWORD

nonn

AUTHOR

Daniel E. Loeb

STATUS

approved