A229617 Number of binary strings of length n containing at most 3 distinct squares, where a square is a nonempty block of the form xx.

1, 2, 4, 8, 16, 32, 64, 128, 210, 324, 438, 588, 758, 928, 1100, 1300, 1400, 1506, 1580, 1624, 1574, 1536, 1550, 1584, 1600, 1644, 1718, 1800, 1910, 2076, 2272, 2484, 2736, 3004, 3306, 3612, 4044, 4456, 4800, 5188, 5664, 6164, 6760, 7380, 7980

Offset

0,2

Links

Table of n, a(n) for n=0..44.

R. C. Entringer, D. E. Jackson and J. A. Schatz, On nonrepetitive sequences, J. Combin. Theory Ser. A. 16 (1974), 159-164.

Crossrefs

Sequence in context: A009641 A089889 A297526 * A306316 A275061 A230177

Adjacent sequences: A229614 A229615 A229616 * A229618 A229619 A229620

Keyword

nonn

Author

Jeffrey Shallit, Sep 26 2013

Status

approved