A291798 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) = preperiod (or threshold) of orbit of that word.

3, 4, 6, 2, 17, 15, 9, 11, 13, 14, 16, 12, 24, 10, 12, 19, 14, 23, 21, 4, 13, 9, 25, 11, 29, 27, 3, 7, 420, 25, 15, 24, 28, 6, 17, 19, 28, 4, 26, 21, 23, 419, 6, 417, 46, 24, 8, 5, 421, 26, 28, 415, 12, 413, 10, 44, 27, 10, 40, 22, 84, 411, 18, 20, 29, 9, 11

Offset

1,1

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 A284119 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, A284119, A291797.

Sequence in context: A055173 A261728 A367806 * A212152 A239810 A333318

Adjacent sequences: A291795 A291796 A291797 * A291799 A291800 A291801

Keyword

nonn

Author

N. J. A. Sloane, Sep 04 2017

Extensions

a(31)-a(67) from Lars Blomberg, Sep 08 2017

Status

approved