NUMBER THEORETIC TECHNIQUES IN THE SETS OF EQUAL RESISTOR NETWORKS
Keywords:
resistor network, number theory, Fibonacci numbers, Haros-Farey sequence, series, parallel, bridge and non-planar circuitsDOI:
https://doi.org/10.17654/0972087125037Abstract
A variety of sets of equivalent resistances can be constructed by combining equal resistors in different configurations using series, parallel or bridge connections. The orders of such sets are traditionally obtained manually for small numbers and computationally, when the numbers are not small. Due to available computer memory, it has not been possible to analyze these sets beyond the case of 30 equal resistors. In this article, we analytically derive a strict lower bound and a strict upper bound for the orders of these sets using inequalities, integer sequences and certain number theoretic techniques. The strict lower bound is obtained using combinatorial arguments and the resulting inequalities. The strict upper bound is obtained by using techniques from number theory, which make use of the Haros-Farey sequence with Fibonacci numbers as their argument. The lower and upper bounds thus obtained hold true for any number of equal resistors as long as they are combined in series and parallel combinations. The various sequences arising in this study are presented in detail with references to the “The On-Line Encyclopedia of Integer Sequences”.
Received: April 13, 2025
Accepted: June 25, 2025
References
[1] Physics Textbook for Class XI and Class XII, National Council of Educational Research and Training, New Delhi, India, 2024. https://ncert.nic.in/.
[2] Mathematics Textbook for Class XI and Class XII, National Council of Educational Research and Training, New Delhi, India, 2024. https://ncert.nic.in/.
[3] A. Halpern, 3000 Solved Problems in Physics, Schaum’s Solved Problem Series, McGraw-Hill, 1988.
[4] S. A. Khan, Introductory Physics Laboratory Manual, LAP LAMBERT Academic Publishing, Germany, 2015. http://isbn.nu/978-3-659-77189-7/.
[5] S. A. Khan, Objective Questions in Introductory Physics, LAP LAMBERT Academic Publishing, Germany, 2015. http://isbn.nu/978-3-659-78619-8/.
[6] R. L. Boylestad, Introductory Circuit Analysis, 11th ed., Pearson International, Prentice Hall, 2007.
[7] A. Amengual, The intriguing properties of the equivalent resistances of n equal resistors combined in series and in parallel, American Journal of Physics 68(2) (2000), 175-179. http://dx.doi.org/10.1119/1.19396.
[8] N. J. A. Sloane, (Editor), The On-Line Encyclopedia of Integer Sequences, 2010. Published Electronically at http://oeis.org/ (accessed April 25, 2025).
[9] T. P. Srinivasan, Fibonacci sequence, golden ratio, and a network of resistors, American Journal of Physics 60(5) (1992), 461-462.
http://dx.doi.org/10.1119/1.16849.
[10] A. D’Amico, C. Falconi, M. Bertsch, G. Ferri, R. Lojacono, M. Mazzotta, M. Santonico and G. Pennazza, The presence of the Fibonacci numbers in passive ladder networks: the case of forbidden bands, IEEE Antennas and Propagation Magazine 56(5) (2014), 275-287. http://dx.doi.org/10.1109/MAP.2014.6971968.
[11] R. A. Dunlap, The Golden Ratio and Fibonacci Numbers, World Scientific, 1997.
[12] G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, Oxford University Press, United Kingdom, 2008.
[13] J. H. Conway and R. K. Guy, The Book of Numbers, Springer-Verlag, Germany, 1996. https://doi.org/10.1007/978-1-4612-4072-3.
[14] T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, Germany, 2013. https://doi.org/10.1007/978-1-4757-5579-4.
[15] MATHEMATICA, Wolfram Research, Inc., 2020.
https://www.wolfram.com/mathematica/ (accessed April 25, 2025).
[16] N. Boccara, Essentials of Mathematica with Applications to Mathematics and Physics, Springer, Germany, 2007. http://dx.doi.org/10.1007/978-0-387-49514-9.
[17] R. Jagannathan, Matrix approach to certain number theoretical problems, Proceedings of the Conference on Matrix algebra, Computational Methods and Number Theory, 6-9 September, 1976, Mysore, India, Convenor: R. Alladi, Editor: N. R. Ranganathan, The Institute of Mathematical Sciences, Madras, India, MATSCIENCE Report, 87 1977, pp. 6-18. Complete Proceedings available from the IMSc Library Digital Repository
http://www.imsc.res.in/xmlui/handle/123456789/287 (accessed April 25, 2025).
[18] R. Jagannathan, On the use of matrix methods in certain number theoretical problems, Proceedings of the Conference on Number Theory, 3-7 August 1980, Ootacamund, India, Convenor: R. Alladi, Editor: R. Jagannathan, The Institute of Mathematical Sciences, Madras. MATSCIENCE Report, 104, pp. 131-138, (1981). Complete Proceedings available from the IMSc Library Digital Repository http://www.imsc.res.in/xmlui/handle/123456789/305 (accessed April 25, 2025).
[19] A. W. Joshi, Matrices and Tensors in Physics, New Age International, New Delhi, India, 2005.
[20] S. A. Khan, An exact matrix representation of Maxwell’s equations, Physica Scripta 71(5) (2005), 440-442.
http://dx.doi.org/10.1238/Physica.Regular.071a00440.
[21] S. A. Khan and R. Jagannathan, A new matrix representation of the Maxwell equations based on the Riemann-Silberstein-Weber vector for a linear inhomogeneous medium, Results in Optics 17 (2024), 100747.
https://doi.org/10.1016/j.rio.2024.100747.
[22] C. Cobeli and Z. Alexandru, The Haros-Farey sequence at two hundred years, Acta Universitatis Apulensis Math. Inform. 5 (2003), 1-38.
http://www.emis.de/journals/AUA/cuprins_1_2003.htm (accessed April 25, 2025).
[23] S. B. Guthery, A Motif of Mathematics, Docent Press, Boston, Massachusetts, U. S. A., 2011. https://www.docentpress.com/books/a-motif-of-mathematics/.
[24] R. H. March, Polygons of resistors and convergent series, American Journal of Physics 61(10) (1993), 900-901. http://dx.doi.org/10.1119/1.17360.
[25] F. J. van Steenwijk, Equivalent resistors of polyhedral resistive structures, American Journal of Physics 66(1) (1998), 90-91.
http://dx.doi.org/10.1119/1.18820.
[26] J. H. Asad, R. S. Hijjawi, A. Sakaj and J. M. Khalifeh, Resistance calculation for an infinite simple cubic lattice application of green’s function, International Journal of Theoretical Physics 43(11) (2004), 2223-2235.
http://dx.doi.org/10.1023/B:IJTP.0000049021.94530.6e.
[27] J. H. Asad, R. S. Hijjawi, A. Sakaj and J. M. Khalifeh, Remarks on perturbation of infinite networks of identical resistors, International Journal of Theoretical Physics 44(4) (2005), 471-483. http://dx.doi.org/10.1007/s10773-005-3977-6.
[28] S. A. Khan, Farey sequences and resistor networks, Mathematical Sciences - Proceedings of the Indian Academy of Sciences 122(2) (2012), pp. 153-182. http://dx.doi.org/10.1007/s12044-012-0066-7.
[29] S. A. Khan, How many equivalent resistances?, Resonance Journal of Science Education 17(5) (2012), 468-475. http://dx.doi.org/10.1007/s12045-012-0050-7.
[30] S. A. Khan, Number Theory and Resistor Networks, Chapter-5 in: Resistors: Theory of Operation, Behavior and Safety Regulations, Editor: R. A. Z. Daou, Nova Science Publishers, New York, 2013, pp. 99-154.
http://www.novapublishers.com/ and
https://novapublishers.com/shop/resistors-theory-of-operation-behavior-and-safety-regulations/.
[31] S. A. Khan, Beginning to count the number of equivalent resistances, Indian Journal of Science and Technology 9(44) (2016), 1-7.
http://dx.doi.org/10.17485/ijst/2016/v9i44/88086.
[32] M. Stampfli, Bridged graphs, circuits and Fibonacci numbers, Applied Mathematics and Computation 302 (2017), 68-79.
http://dx.doi.org/10.1016/j.amc.2016.12.030.
[33] S. A. Khan, Mathematical properties of resistor networks, Proceedings of the International Conference on Advances in Multi-disciplinary Sciences and Engineering Research, (ICAMSER-2021), (2-4 July 2021, Chitkara University, Baddi Solan, Himachal Pradesh, India), Editors: A. L. Srivastav, A. Kumar, S. Batra, M. Gupta, N. Kumra, A. Taneja, I. Dutt and S. R. Sharma, AIP Conference Proceedings, American Institute of Physics, 2451, (2022), pp. 020013.
https://doi.org/10.1063/5.0095174.
[34] P. P. Korovkin, Inequalities, Mir Publishers, Moscow, Russia, 1975.
[35] Microsoft EXCEL, http://www.microsoft.com/ (accessed April 25, 2025).
[36] S. A. Khan, Doing numerical calculus using Microsoft EXCEL, Indian Journal of Science and Technology 9(44) (2016), 1-5.
http://dx.doi.org/10.17485/ijst/2016/v9i44/87217.
[37] S. A. Khan, Microsoft EXCEL for Numerical Calculus, Chapter-5 in: Focus on Calculus, Editor: S. G. Georgiev, Nova Science Publishers, New York, 2020, pp. 177-201. http://www.novapublishers.com/,
https://novapublishers.com/shop/focus-on-calculus/.
[38] S. A. Khan, Cylindrometer, The Physics Teacher 48(9) (2010), 607.
http://dx.doi.org/10.1119/1.3517029.
[39] S. A. Khan, Coordinate Geometric Generalization of the Spherometer and Cylindrometer, Chapter-8 in: Advances in Engineering Research, Volume 10, Editor: V. M. Petrova, Nova Science Publishers, New York, 2015, pp. 163-190. http://www.novapublishers.com/ and
https://novapublishers.com/shop/advances-in-engineering-research-volume-10/.
[40] S. A. Khan, Coordinate geometric generalization of the spherometer, Far East Journal of Mathematical Sciences (FJMS) 101(3) (2017), 619-642.
http://dx.doi.org/10.17654/MS101030619.
[41] S. A. Khan, Primes in geometric-arithmetic progression, Global Journal of Pure and Applied Mathematics 12(2) (2016), 1161-1180.
http://www.ripublication.com/gjpam16/gjpamv12n2_01.pdf.
[42] S. A. Khan, Sums of the powers of reciprocals of polygonal numbers, International Journal of Applied Mathematics 33(2) (2020), 265-282.
http://dx.doi.org/10.12732/ijam.v33i2.6.
[43] S. A. Khan, Tabular integration by parts, Resonance Journal of Science Education 27(6) (2022), 1049-1060. https://doi.org/10.1007/s12045-022-1396-0.
[44] S. A. Khan, F. M. N. Al Khrusi, G. M. J. Al Saadi, A. T. J. Alkasbi, M. A. Al Amri and M. A. Tabook, A general theory of orthogonal polynomials, Advances in Mathematics Research, Volume 38, Editor: A. R. Baswell, Nova Science Publishers, New York, USA, 2025.
http://www.novapublishers.com/.
[45] S. A. Khan, K. S. O. N. Al Shaqsi, L. M. A. Al Mamari, A. S. A. H. Albalushi, M. A. Tabook and M. A. Al Amri, Qualitative Theory of Differential Equations, Advances in Mathematics Research, Vol. 38, Editor: A. R. Baswell, Nova Science Publishers, New York, USA, 2025. http://www.novapublishers.com/.
[46] S. A. Khan, Trigonometric ratios using geometric methods, Advances in Mathematics: Scientific Journal 9(10) (2020), 8685-8702.
https://doi.org/10.37418/amsj.9.10.94.
[47] S. A. Khan, Teaching irrational numbers through trigonometry, Resonance Journal of Science Education 26(6) (2021), 813-827.
https://doi.org/10.1007/s12045-021-1181-5.
[48] S. A. Khan, Trigonometric ratios using algebraic methods, Mathematics and Statistics 9(6) (2021), 899-907. http://dx.doi.org/10.13189/ms. 2021.090605.
[49] S. A. Khan, A Comprehensive Introduction to Trigonometry, Chapter-2 in: Advances in Mathematics Research, Volume 30, Editor: A. R. Baswell, Nova Science Publishers, New York, USA, 2022, pp. 31-104.
https://doi.org/10.52305/BDFQ3979 and
https://novapublishers.com/shop/advances-in-mathematics-research-volume-30/.
[50] S. A. Khan, E. C. G. Sudarshan and the quantum mechanics of charged particle beam optics, Current Science 115(9) (2018), 1813-1814.
http://www.currentscience.ac.in/Volumes/115/09/1813.pdf.
[51] R. Jagannathan and S. A. Khan, Quantum Mechanics of Charged Particle Beam Optics: Understanding Devices from Electron Microscopes to Particle Accelerators, CRC Press, Taylor & Francis, 2019, p. 356.
https://doi.org/10.1201/9781315232515.
[52] S. A. Khan and R. Jagannathan, Quantum mechanics of bending of a charged particle beam by a dipole magnet, Advances in Imaging and Electron Physics 229 (2024), 1-41. https://doi.org/10.1016/bs.aiep.2024.02.001.
[53] R. Jagannathan and S. A. Khan, On the deformed oscillator and the deformed derivative associated with the Tsallis q-exponential, International Journal of Theoretical Physics 59(8) (2020), 2647-2669.
http://dx.doi.org/10.1007/s10773-020-04534-w.
[54] S. A. Khan and R. Jagannathan, On certain appell polynomials and their generalizations based on the Tsallis q-exponential, Bulletin of the Malaysian Mathematical Sciences Society 45(4) (2022), 1453-1472.
http://dx.doi.org/10.1007/s40840-022-01292-2.
[55] S. A. Khan, Polarization in maxwell optics, Optik-International Journal for Light and Electron Optics 131 (2017), 733-748.
http://dx.doi.org/10.1016/j.ijleo.2016.11.134.
[56] S. A. Khan, Quantum methodologies in maxwell optics, Advances in Imaging and Electron Physics 201 (2017), 57-135.
http://dx.doi.org/10.1016/bs.aiep.2017.05.003.
[57] S. A. Khan, Cross polarization in Gaussian and Bessel light beams, Optics Communications 545 (2023), 129728.
https://doi.org/10.1016/j.optcom.2023.129728.
[58] S. A. Khan, A matrix differential operator for passage from scalar to vector optics, Results in Optics 13 (2023), 100527. https://doi.org/10.1016/j.rio.2023.100527.
[59] S. A. Khan, Anisotropic airy beams, Results in Optics 13 (2023), 100569. https://doi.org/10.1016/j.rio.2023.100569.
[60] S. A. Khan, Cross polarization in anisotropic Gaussian light beams, Indian Journal of Physics 98 (2024), 3699-3705. https://doi.org/10.1007/s12648-024-03121-7.
[61] S. A. Khan and R. Jagannathan, A matrix formalism of the Maxwell vector wave optics including polarization, Advances in Imaging and Electron Physics 235 (2025), 1-111. https://doi.org/10.1016/bs.aiep.2025.06.002.
[62] S. A. Khan, Passage from scalar to vector optics and the Mukunda-Simon-Sudarshan theory for paraxial systems, Journal of Modern Optics 63(17) (2016), 1652-1660. http://dx.doi.org/10.1080/09500340. 2016.1164257.
[63] S. A. Khan, Quantum methodologies in Helmholtz optics, Optik-International Journal for Light and Electron Optics 127(20) (2016), 9798-9809.
http://dx.doi.org/10.1016/j.ijleo.2016.07.071.
[64] S. A. Khan, Quantum methods in light beam optics, Optics and Photonics News 27(12) (2016), 47. https://doi.org/10.1364/OPN.27.12.000047. One of the thirty summaries selected under the theme, Optics in 2016, highlighting the most exciting peer-reviewed optics research to have emerged over the past 12 months. The summary of the two selected papers [62, 63] is described in this publication. https://www.optica-opn.org/home/articles/volume_13/issue_11/departments/ global_optics/global_optics/.
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Copyright ©2025 The Author(s)

This work is licensed under a Creative Commons Attribution 4.0 International License.
_________________________
Attribution: Credit Pushpa Publishing House as the original publisher, including title and author(s) if applicable.
Non-Commercial Use: For non-commercial purposes only. No commercial activities without explicit permission.
Contact Puspha Publishing House for more info or permissions.
