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A291799 Take n-th word over {1,2} listed in A291797 and apply the Post tag system described in A284116 (but adapted to the alphabet {1,2}); a(n) = period of orbit of that word, or 0 if the orbit ends at the empty word. 1
0, 2, 0, 2, 6, 6, 0, 0, 0, 6, 6, 6, 6, 6, 0, 6, 0, 6, 6, 2, 6, 6, 6, 6, 6, 6, 4, 6, 0, 6, 0, 6, 6, 4, 0, 0, 6, 6, 6, 0, 0, 0, 6, 0, 6, 6, 4, 6, 0, 6, 6, 0, 6, 0, 6, 6, 0, 6, 6, 6, 10, 0, 0, 0, 6, 6, 4, 6, 6, 6, 0, 4, 0, 0, 0, 6, 6, 6, 0, 6, 4, 6, 6, 2, 6, 6, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Post's tag system maps a word w over {1,2} to w', where if w begins with 1, w' is obtained by appending 11 to w and deleting the first three letters, or if w begins with 2, w' is obtained by appending 2212 to w and deleting the first three letters.

We work over {1,2} rather than the official alphabet {0,1} because of the prohibition in the OEIS of terms (other than 0 itself) which begin with 0.

This is an analog of A291793 (or A284121) for the words in A291797.

LINKS

Lars Blomberg, Table of n, a(n) for n = 1..8190 (For terms in A291797 up to length 36.)

Peter R. J. Asveld, On a Post's System of Tag. Bulletin of the EATCS 36 (1988), 96-102. See Table 3.

CROSSREFS

Cf. A284116, A284121, A291793, A291797.

Sequence in context: A185197 A157491 A094385 * A295027 A225479 A156815

Adjacent sequences:  A291796 A291797 A291798 * A291800 A291801 A291802

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 04 2017

EXTENSIONS

a(31)-a(87) from Lars Blomberg, Sep 08 2017

STATUS

approved

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Last modified July 17 02:10 EDT 2019. Contains 325092 sequences. (Running on oeis4.)