4 research outputs found

    On two stronger versions of Dejean's conjecture

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    Repetition threshold is the smallest number RT(n) such that infinitely many n-ary words contain no repetition of order greater than RT(n). These "extremal" repetition-free words are called threshold words. All values of RT(n) are now known, since the celebrated Dejean's conjecture (1972) was finally settled in 2009. We study two questions about threshold words. First, does the number of n-ary threshold words grow exponentially with length? This is the case for 3 ≤ n ≤ 10, and a folklore conjecture suggests an affirmative answer for all n ≥ 3. Second, are there infinitely many n-ary threshold words containing only finitely many different repetitions of order RT(n)? The answer is "yes" for n = 3, but nothing was previously known about bigger alphabets. For odd n = 7,9,...,101, we prove the strongest possible result in this direction. Namely, there are exponentially many n-ary threshold words containing no repetitions of order RT(n) except for the repeats of just one letter. © 2012 Springer-Verlag

    Outlines of the Political History of Michigan

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    Written in 1876 this work was originally intended as a sketch of the political development of the State of Michigan to be used for the purposes of its Centennial Committee. Chapters span Michigan political history beginning with early explorations by France and England, colonization, French and then British rule, military conquest, the administration of colonial governors, relations with adjacent territorial entities, the last years of the Territory and the first Constitution of 1835; and lastly, Michigan under the Constitution of 1850.https://repository.law.umich.edu/books/1047/thumbnail.jp
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