

A261896


Consider the 2^n values of A162795(i)/i^2 for 2^n <= i < 2^(n+1); a(n) = value of i where this quantity is minimized.


1



3, 5, 11, 25, 43, 89, 179, 361, 727, 1459, 2921, 5843, 11689, 23383, 46769, 93543, 187093, 374193, 748391, 1496785, 2993575, 5987157, 11974321, 23948647, 47897299, 95794607, 191589221, 383178449, 766356903, 1532713827, 3065427663, 6130855333, 12261710675, 24523421357, 49046842723
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OFFSET

0,1


COMMENTS

Sequence suggested by Omar E. Pol.
Note that all values in this sequence are odd and that a(n) is approximately 2*a(n1).


REFERENCES

D. Applegate, O. E. Pol and N. J. A. Sloane, The toothpick sequence and other sequences from cellular automata, Congressus Numerantium, v. 206 (2010) 157191.


LINKS

Table of n, a(n) for n=0..34.
D. Applegate, O. E. Pol and N. J. A. Sloane, The toothpick sequence and other sequences from cellular automata; also available at arXiv:1004.3036v2, [math.CO], 2010.
Steven R. Finch, Toothpicks and Live Cells, July 21, 2015. [Cached copy, with permission of the author]
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS


MATHEMATICA

T = 1; t[0] = 0; t[1] = 1; lst = {1};
Do[twon = 2^n; Tmin = 1; imin = 1;
Do[If[i==twon, t[i]=twon,
t[i]=2*t[itwon]+t[itwon+1];
If[OddQ[i], T=T+t[i];
Ttest=T/(i*i)];
If[Ttest<Tmin, Tmin=Ttest; imin=i ]],
{i, twon, 2*twon  1}];
AppendTo[lst, imin],
{n, 1, 15}];
lst
N[Tmin, 10]


CROSSREFS

Cf. A139250, A147562, A162795, A170927, A195853, A260239, A261313, A261895.
Sequence in context: A018116 A259643 A167796 * A285184 A018008 A104545
Adjacent sequences: A261893 A261894 A261895 * A261897 A261898 A261899


KEYWORD

nonn


AUTHOR

Robert Price, Sep 05 2015


STATUS

approved



