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On the Period Length Modulo p of the Numerators of Convergents for the Square Root of a Prime Number p

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Mathematical Modeling and Supercomputer Technologies (MMST 2022)

Abstract

In this paper, we investigate the properties of the sequence of numerators of convergents for the square root of a prime number. It is proved that the period length L of this sequence modulo p is equal to l,  2l or 4l,  where l is the period length of the continued fraction for the square root of the prime p. Namely, if the remainder of dividing p by 8 is equal to 7,  then \(L=l;\) if the remainder of dividing p by 8 is equal to 3,  then \(L=2l;\) if the remainder of dividing p by 4 is equal to 1,  then \(L=4l.\)

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Acknowledgements

The authors are grateful to anonymous reviewers for valuable comments.

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Correspondence to S. V. Sidorov .

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Sidorov, S.V., Shcherbakov, P.A. (2022). On the Period Length Modulo p of the Numerators of Convergents for the Square Root of a Prime Number p. In: Balandin, D., Barkalov, K., Meyerov, I. (eds) Mathematical Modeling and Supercomputer Technologies. MMST 2022. Communications in Computer and Information Science, vol 1750. Springer, Cham. https://doi.org/10.1007/978-3-031-24145-1_11

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  • DOI: https://doi.org/10.1007/978-3-031-24145-1_11

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