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A019311 Number of words of length n (n >= 1) over a two-letter alphabet having a minimal period of size n-2. 0
0, 0, 2, 2, 6, 12, 28, 48, 106, 198, 414, 800, 1644, 3236, 6546, 12982, 26130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

H. Harborth, Endliche 0-1-Folgen mit gleichen Teilblöcken, J. für Reine Angewandte Math. 271 (1974), 139-154.

LINKS

Table of n, a(n) for n=1..17.

CROSSREFS

Sequence in context: A217211 A035615 A115962 * A216215 A052994 A088219

Adjacent sequences:  A019308 A019309 A019310 * A019312 A019313 A019314

KEYWORD

nonn

AUTHOR

Jeffrey Shallit

EXTENSIONS

More terms from Jeffrey Shallit, Feb 20 2013

STATUS

approved

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Last modified December 3 16:24 EST 2016. Contains 278745 sequences.