The convergence of sequences in terms of positive and alternating Perron expansions
DOI:
https://doi.org/10.17721/1812-5409.2026/1.9Keywords:
Lüroth expansions, Engel expansions, Pierce expansions, convergence of sequences, Perron expansionsAbstract
In this paper we study conditions for the convergence of sequences in terms of positive and alternating Perron expansions of real numbers (P-representation and P−-representation). These conditions make it possible to verify the continuity of functions defined via the P-representation or P−-representation.
The main results of this work are as follows. First, we systematically consider all possible cases and, by taking into account the geometric structure of Perron expansions, significantly reduce the number of distinct cases that require separate analysis. Second, for each case, we formulate and rigorously prove a convergence condition that is both necessary and sufficient. Third, the results are obtained not for specific expansions (such as the Engel or Pierce expansions), but for the Perron expansions, which include many classical representations of real numbers as special cases.
These results provide a foundation for further analysis of fractal functions defined through Perron expansions or their special cases (the Lüroth, Engel, Pierce, and Sylvester expansions).
Pages of the article in the issue: 72 - 77
Language of the article: English
References
Albeverio, S., Baranovskyi, O., Kondratiev, Y., & Pratsiovytyi, M. (2013). On one class of functions related to Ostrogradsky series and containing singular and nowhere monotonic functions. Naukovyj chasopys NPU imeni M. P. Drahomanova. Seriya 1. Fizyko-matematychni nauky, 15, 35–55.
Baranovskyi, O., & Pratsiovytyi, M. (2023). One class of continuous functions with complicated local properties related to Engel series. Functiones et Approximatio, Commentarii Mathematici, 68(2), 143–162. https://doi.org/10.7169/facm/1963
Erdős, P., Rényi, A., & Szusz, P. (1958). On Engel’s and Sylvester’s series. Annales Universitatis Scientarium Budapestinensis de Rolando Eötvös Nominatae, Sectio Mathematica, 1, 7–32.
Galambos, J. (1976). Representations of Real Numbers by Infinite Series. Springer. https://doi.org/10.1007/BFb0081642
Galambos, J. (1998). Further metric results on series expansions. Publicationes Mathematicae Debrecen, 52(3-4), 377–384. http://dx.doi.org/10.5486/PMD.1998.2037
Kalpazidou, S., Knopfmacher, A., & Knopfmacher, J. (1990). Lüroth-type alternating series representations for real numbers. Acta Arithmetica, 55(4), 311–322. https://doi.org/10.4064/aa-55-4-311-322
Moroz, M. (2017). Projector of the ∆O-representation of numbers into the ∆E-representation. Transactions of Institute of Mathematics of NAS of Ukraine, 14(4), 49–64 [in Ukrainian].
Moroz, M. (2024). Representation of Real Numbers by Perron Series, Their Geometry, and Some Applications. Journal of Mathematical Sciences, 279(3), 384–399. https://doi.org/10.1007/s10958-024-07020-4
Moroz, M. (2025). Representation of real numbers by alternating Perron series and their geometry. Expositiones Mathematicae, 43(1), 1–18. https://doi.org/10.1016/j.exmath.2024.125635
Oppenheim, A. (1972). The representation of real numbers by infinite series of rationals. Acta Arithmetica, 21(1), 391–398.https://doi.org/10.4064/aa-21-1-391-398
Prats’ovytyi, M., Baranovs’kyi, O., & Maslova, Y. (2021). Generalization of the Tribin Function. Journal of Mathematical Sciences, 253(2), 276–288. https://doi.org/10.1007/s10958-021-05227-3
Shallit, J. O. (1986). Metric theory of Pierce expansions. The Fibonacci Quarterly, 24(1), 22–40. https://doi.org/10.1080/00150517.1986.12429786
Sydoruk, L., & Torbin, G. (2017). On singularity of distribution of random variables with independent symbols of Oppenheim expansions. Modern Stochastics: Theory and Applications, 4(3), 273–283. https://doi.org/10.15559/17-VMSTA87
Torbin, G., & Pratsyovyta, I. (2010). Singularity of the second Ostrogradskiĭ random series. Theory of Probability and Mathematical Statistics, 81, 187–195. https://doi.org/10.1090/S0094-9000-2011-00819-8
Zhykharyeva, Y., & Pratsiovytyi, M. (2012). Expansions of numbers in positive Lüroth series and their applications to metric, probabilistic and fractal theories of numbers. Algebra and Discrete Mathematics, 14(1), 145–160.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Mykola Moroz

This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
