

A285196


If A_k denotes the first 2*3^k terms, then A_0 = 01, A_{k+1} = A_k A_k B_k, where B_k is obtained from A_k by interchanging 0's and 1's.


2



0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0
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OFFSET

0


COMMENTS

In other words, the sequence is the limit of A_k as k > oo.
This is a cubefree sequence.


REFERENCES

J.P. Allouche and J. Shallit, Automatic Sequences, Cambridge Univ. Press, 2003, p. 28, #49.


LINKS

Table of n, a(n) for n=0..100.


MAPLE

with(ListTools);
f2:=proc(S) map(x>x+1 mod 2, S); end;
f:=proc(S) global f2;
[op(S), op(S), op(f2(S))]; end;
S:=[0, 1];
for n from 1 to 6 do S:=f(S): od:
S;


CROSSREFS

See A064990 for a very similar sequence.
The ThueMorse sequence A010060 is a classical example of a cubefree sequence.
A282317 is the lexicographically earliest binary cubefree sequence.
Sequence in context: A286685 A284878 A118006 * A189673 A189014 A189017
Adjacent sequences: A285193 A285194 A285195 * A285197 A285198 A285199


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Apr 30 2017


STATUS

approved



