%I M0712 #57 Mar 09 2022 16:47:10

%S 1,1,1,2,3,5,9,16,28,51,93,170,315,585,1092,2048,3855,7281,13797,

%T 26214,49932,95325,182361,349525,671088,1290555,2485513,4793490,

%U 9256395,17895697,34636833,67108864,130150524,252645135,490853405,954437176,1857283155,3616814565

%N a(n) = floor(2^(n-1)/n).

%C Very close to A000048. [Fisher, 1989]

%C 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

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

%H Vincenzo Librandi, <a href="/A006788/b006788.txt">Table of n, a(n) for n = 1..1000</a>

%H H. L. Fisher, <a href="/A027601/a027601.pdf">Letter to N. J. A. Sloane, Mar 16 1989</a>

%H Simon Michalowsky, Bahman Gharesifard and Christian Ebenbauer, <a href="https://arxiv.org/abs/1711.05486">A Lie bracket approximation approach to distributed optimization over directed graphs</a>, arXiv:1711.05486 [math.OC], 2017.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HappyEndProblem.html">Happy End Problem</a>

%t Table[Quotient[2^n, 2*n], {n, 1, 60}] (* _Vladimir Joseph Stephan Orlovsky_, May 07 2011 *)

%o (Magma) [Floor(2^(n-1)/n) : n in [1..40]]; // _Vincenzo Librandi_, Sep 24 2011

%o (Sage)

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

%o [A006788(n) for n in (1..38)] # _Peter Luschny_, Sep 18 2014

%o (Python)

%o print([2**(n-1)//n for n in range(1, 40)]) # _Gennady Eremin_, Feb 04 2022

%Y Cf. A054650, A000048.

%K nonn

%O 1,4

%A _N. J. A. Sloane_