Brahmagupta Triangles in Generalized Fibonacci Sequences

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Kanwara Mukkhata
Sompong Chuysurichay

Abstract

For any positive integers equation and equation, define the sequence equation by equationequation, and equation for all equation. A Brahmagupta triangle is a triangle all of whose side lengths are consecutive positive integers with integral area. In this paper, we prove that for any given  equation and equation, there is at most one Brahmagupta triangle all of whose side lengths are elements of equation. Moreover, we characterize all initial values equation for which the sequence equation contains a Brahmagupta triangle, and show that this occurs precisely in two Pell-parametrized families.

Article Details

How to Cite
Mukkhata, K., & Chuysurichay, S. (2026). Brahmagupta Triangles in Generalized Fibonacci Sequences. KKU Science Journal, 54(2), 530–537. https://doi.org/10.14456/kkuscij.2026.37
Section
Research Articles

References

Andreescu, T., Andrica, D. and Cucurezeanu, I. (2010). An Introduction to Diophantine Equations: A Problem-Based Approach. New York: Birkha ̈user. 92 - 93.

Bailey, H. and Gosnell, W. (2012). Heronian triangles with sides in arithmetic progression: an inradius perspective. Mathematics Magazine 85(4): 290 - 294. doi: 10.4169/math.mag.85.4.290.

Beauregard, R.A. and Suryanarayan, E.R. (1998). The Brahmagupta Triangles. The College Mathematics Journal 29(1): 13 - 17. doi: 10.1080/07468342.1998.11973907.

Carmichael, R.D. (1959). The Theory of Numbers and Diophantine Analysis. New York: Dover.

Gould, H.W. (1973). A Triangle with Integral Sides and Area. The Fibonacci Quarterly 11(1): 27 - 39. doi: 10.1080/00150517.1973.12430863.

Harborth, H. and Kemnitz, A. (1988). Fibonacci triangles, in: G.E. Bergum et al. (eds), Applications of Fibonacci Numbers, Kluwer Academic Publishers (Dordrecht, 1990): 129 - 132. doi: 10.1007/978-94-009-1910-5_14.

Harborth, H., Kemnitz, A. and Robbins, N. (1996). Non-existence of Fibonacci triangles. Congressus Numerantium 114: 29 - 31.

Nelsen, R.B. (2020). Almost Equilateral Heronian Triangles. Mathematics Magazine 93(5): 378 - 379. doi: 10.1080/0025570X.2020.1817708.