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A006788 Floor( 2^(n-1)/n ).
(Formerly M0712)
5
1, 1, 1, 2, 3, 5, 9, 16, 28, 51, 93, 170, 315, 585, 1092, 2048, 3855, 7281, 13797, 26214, 49932, 95325, 182361, 349525, 671088, 1290555, 2485513, 4793490, 9256395, 17895697, 34636833, 67108864, 130150524, 252645135, 490853405, 954437176, 1857283155, 3616814565 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Very close to A000048 [Fisher, 1989]

This is the number of nested polygons needed to produce a graph that is always concave, see the MathWorld article. - Jon Perry, Sep 15 2002

REFERENCES

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

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

H. L. Fisher, Letter to N. J. A. Sloane, Mar 16 1989

MathWorld, Happy End Problem

Simon Michalowsky, Bahman Gharesifard, Christian Ebenbauer, A Lie bracket approximation approach to distributed optimization over directed graphs, arXiv:1711.05486 [math.OC], 2017.

MATHEMATICA

Table[Quotient[2^n, 2*n], {n, 1, 60}] (* Vladimir Joseph Stephan Orlovsky, May 07 2011 *)

PROG

(MAGMA) [Floor( 2^(n-1)/n) : n in [1..40]]; // Vincenzo Librandi, Sep 24 2011

(Sage)

A006788 = lambda n: (1<<n)//(2*n)

[A006788(n) for n in (1..38)] # Peter Luschny, Sep 18 2014

CROSSREFS

Cf. A054650, A000048.

Sequence in context: A000048 A056303 A074099 * A054650 A022857 A000691

Adjacent sequences:  A006785 A006786 A006787 * A006789 A006790 A006791

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified January 16 06:59 EST 2019. Contains 319188 sequences. (Running on oeis4.)