

A088205


Infinite audioactive word that shifts 1 place left under "Look and Say" method A, starting with a(0)=0.


1



0, 1, 0, 1, 1, 1, 0, 3, 1, 1, 0, 1, 3, 2, 1, 1, 0, 1, 1, 1, 3, 1, 2, 2, 1, 1, 0, 3, 1, 1, 3, 1, 1, 2, 2, 2, 1, 1, 0, 1, 3, 2, 1, 1, 3, 2, 1, 3, 2, 2, 1, 1, 0, 1, 1, 1, 3, 1, 2, 2, 1, 1, 3, 1, 2, 1, 1, 1, 3, 2, 2, 2, 1, 1, 0, 3, 1, 1, 3, 1, 1, 2, 2, 2, 1, 1, 3, 1, 1, 1, 2, 3, 1, 1, 3, 3, 2, 2, 1, 1, 0, 1, 3, 2, 1
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OFFSET

0,8


COMMENTS

Positions of zero are given by A088206.
The sequence is obtained by starting with 0 and then successively appending the count (number of repetitions) and the value which is seen, term after term: "one zero, one one, one zero, three ones, one zero, ...". Otherwise said, the sequence is defined by "Start with 0 and append the result of "Look and Say" applied to the sequence". The "shifted left under Look and Say" property is thus an immediate consequence of the definition. A less trivial property is that there cannot be a number larger than 3 in this sequence.  M. F. Hasler, Jul 28 2015


LINKS

Table of n, a(n) for n=0..104.


EXAMPLE

The initial terms {0,1,0,1,1,1,0,3,1,1,0,...} are shifted 1 place left by saying: "one 0, one 1, one 0, three 1's, one 0, ...", which drops the leading 0 to give {1,0,1,1,1,0,3,1,1,0,...}.


PROG

(PARI) a=List(0); my(i=1); while(#a<200, listput(a, 1); listput(a, a[i]); while(a[i++]==a[#a], a[#a1]++)); a \\ M. F. Hasler, Jul 28 2015


CROSSREFS

Cf. A088206, A088203, A087282, A005150.
Sequence in context: A062172 A196838 A284376 * A318923 A336111 A244657
Adjacent sequences: A088202 A088203 A088204 * A088206 A088207 A088208


KEYWORD

nonn


AUTHOR

Paul D. Hanna, Sep 22 2003


STATUS

approved



