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On the number of distinct exponents in the prime factorization of an integer

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Abstract

Let f(n) be the number of distinct exponents in the prime factorization of the natural number n. We prove some results about the distribution of f(n). In particular, for any positive integer k, we obtain that

$$\begin{aligned} \#\{n \le x : f(n) = k\} \sim A_k x \end{aligned}$$

and

$$\begin{aligned} \#\{n \le x : f(n) = \omega (n) - k\} \sim \frac{B x (\log \log x)^k}{k! \log x}, \end{aligned}$$

as \(x \rightarrow +\infty \), where \(\omega (n)\) is the number of prime factors of n and \(A_k, B > 0\) are some explicit constants. The latter asymptotic extends a result of Aktaş and Ram Murty (Proc. Indian Acad. Sci. (Math. Sci.) 127(3) (2017) 423–430) about numbers having mutually distinct exponents in their prime factorization.

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References

  1. Aktaş K and Ram Murty M, On the number of special numbers, Proc. Indian Acad. Sci. (Math. Sci.) 127(3) (2017) 423–430

    Article  MathSciNet  Google Scholar 

  2. Cao H Z, On the average of exponents, Northeast. Math. J. 10(3) (1994) 291–296

    MathSciNet  MATH  Google Scholar 

  3. Cao H Z, Functions involving the number of prime factors of a natural number, Acta Math. Sinica (Chin. Ser.) 39(5) (1996) 602–608

    MathSciNet  MATH  Google Scholar 

  4. De Koninck J-M, Sums of quotients of additive functions, Proc. Amer. Math. Soc. 44 (1974) 35–38

    Article  MathSciNet  Google Scholar 

  5. De Koninck J-M and Ivić A, Sums of reciprocals of certain additive functions, Manuscripta Math. 30(4) (1979/80) 329–341

  6. De Koninck J-M and Luca F, Analytic number theory, Graduate Studies in Mathematics, vol. 134, American Mathematical Society, Providence, RI (2012) Exploring the anatomy of integers

  7. Duncan R L, On the factorization of integers, Proc. Amer. Math. Soc. 25 (1970) 191–192

    MathSciNet  MATH  Google Scholar 

  8. Duncan R L, Some applications of the Turán–Kubilius inequality, Proc. Amer. Math. Soc. 30 (1971) 69–72

    MathSciNet  MATH  Google Scholar 

  9. Golomb S W, Powerful numbers, Amer. Math. Monthly 77 (1970) 848–855

    Article  MathSciNet  Google Scholar 

  10. Hazlewood D G, On \(k\)-free integers with small prime factors, Proc. Amer. Math. Soc. 52 (1975) 40–44

    MathSciNet  MATH  Google Scholar 

  11. Kátai I and Subbarao M V, On the maximal and minimal exponent of the prime power divisors of integers, Publ. Math. Debrecen 68(3–4) (2006) 477–488

    MathSciNet  MATH  Google Scholar 

  12. Landau E, Sur quelques problèmes relatifs à la distribution des nombres premiers, Bull. Soc. Math. France 28 (1900) 25–38

    Article  MathSciNet  Google Scholar 

  13. Niven I, Averages of exponents in factoring integers, Proc. Amer. Math. Soc. 22 (1969) 356–360

    Article  MathSciNet  Google Scholar 

  14. Recamán Santos B, Consecutive numbers with mutually distinct exponents in their canonical prime factorization, http://mathoverflow.net/questions/201489

  15. Sinha K, Average orders of certain arithmetical functions, J. Ramanujan Math. Soc. 21(3) (2006) 267–277

    MathSciNet  MATH  Google Scholar 

  16. Sloane N J A, The On-Line Encyclopedia of Integer Sequences, http://oeis.org

  17. Suryanarayana D and Sitaramachandra Rao R, The number of square-full divisors of an integer, Proc. Amer. Math. Soc. 34 (1972) 79–80

    Article  MathSciNet  Google Scholar 

  18. Suryanarayana D and Sitaramachandra Rao R, On the maximum and minimum exponents in factoring integers, Arch. Math. (Basel) 28(3) (1977) 261–269

    Article  MathSciNet  Google Scholar 

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Acknowledgements

The author is thankful to the anonymous referee for carefully reading the paper and providing useful suggestions. The author is a member of the INdAM group GNSAGA and, during the preparation of this work, was supported by a postdoctoral fellowship of INdAM.

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Correspondence to Carlo Sanna.

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Communicating Editor: Sanoli Gun

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Sanna, C. On the number of distinct exponents in the prime factorization of an integer. Proc Math Sci 130, 27 (2020). https://doi.org/10.1007/s12044-020-0556-y

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