

A274451


Number of possible sets of antipower periods for binary strings of length n.


4



1, 2, 1, 2, 1, 4, 1, 3, 2, 2, 1, 6, 1, 2, 4, 3, 1, 5, 1, 6, 4, 2, 1, 11, 2, 2, 2, 6, 1, 10, 1, 4
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OFFSET

1,2


COMMENTS

An antiperiod of a lengthn string x is a divisor l of n such that if you factor x as the concatenation of (n/l) blocks of length l, then all these blocks are distinct.


LINKS

Table of n, a(n) for n=1..32.
G. Fici, A. Restivo, M. Silva, and L. Q. Zamboni, Antipowers in infinite words, arxiv preprint, 1606.02868v1 [cs.DM], June 9 2016.


EXAMPLE

For n = 12 there are six possible sets, achieved by the string that follows each: {12} 000000000000; {6,12} 000000000001; {4,6,12} 000000010010; {4,12} 000001000001; {3,4,6,12} 000001010011; {3,6,12} 000001010101.


CROSSREFS

Cf. A274409, A274449, A274450.
Sequence in context: A256608 A279186 A164799 * A193787 A072614 A287597
Adjacent sequences: A274448 A274449 A274450 * A274452 A274453 A274454


KEYWORD

nonn


AUTHOR

Jeffrey Shallit, Jun 23 2016


EXTENSIONS

a(19)a(32) from Bjarki Ágúst Guðmundsson, Jul 07 2016


STATUS

approved



