A291794 Consider Post's tag system applied to the word (100)^n; a(n) = length of first word we see that is in the cycle, if the orbit cycles, or 0 if the orbit reaches the empty string, or -1 if the orbit is unbounded.

5, 15, 15, 19, 0, 31, 85, 37, 31, 37, 55, 37, 0, 0, 91, 85, 31, 127, 31, 33, 37, 0, 37, 37, 0, 73, 73, 163, 55, 19, 73, 157, 37, 73, 37, 37, 37, 163, 55, 37, 163, 37, 37, 85, 37, 0, 0, 85, 37, 127, 91, 37, 37, 0, 37, 69, 19, 31, 163, 163, 87, 55, 0, 37, 0, 55

Offset

1,1

Links

Lars Blomberg, Table of n, a(n) for n = 1..6075

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

Crossrefs

Cf. A284116 and the cross-references there.

Sequence in context: A298265 A366419 A309620 * A321775 A166621 A330082

Adjacent sequences: A291791 A291792 A291793 * A291795 A291796 A291797

Keyword

nonn

Author

N. J. A. Sloane, Sep 04 2017

Extensions

a(33) and beyond from Lars Blomberg, Apr 19 2018

Status

approved