Research Article

NARAYANA'S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS

Volume: 12 Number: 1 October 18, 2026

NARAYANA'S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS

Abstract

In this paper, we consider the Diophantine equation $P_n - P_m = N_k$ in positive integers $n, m$ and $k$ with $n > m \ge 1$, where $P_n$ is the $n$-th Pell number and $N_k$ is the $k$-th Narayana's cows number. We completely solve this equation by using a lower bound for linear forms in logarithms due to Matveev and a version of the Baker-Davenport reduction method due to Dujella and Peth\H{o}.

Keywords

References

  1. BAKER, A. AND DAVENPORT, H., The equations 3x^2-2=y^2 and 8x^2-7=z^2, Q. J. Math. Oxford Ser. (2) 20 (1969), 129--137.
  2. BRAVO, J. J. AND LUCA, F., On a conjecture about repdigits in k-generalized Fibonacci sequences, Publ. Math. Debrecen 82 (2013), no. 3-4, 623--639.
  3. ÇAĞMAN, A., Repdigits as sums of three Half-companion Pell numbers, Miskolc Mathematical Notes, 24 (2023a), no. 2, 687-697.
  4. ÇAĞMAN, A., On Repdigits as Product of Pell and Narayana Numbers, Turkish Journal of Science, 8 (2023b), no. 3, 102–106. DOI: 10.66833/TJOS-2023-0011.
  5. ÇAĞMAN, A., An approach to Pillai's problem with the Pell sequence and the powers of 3, Miskolc Math. Notes 22 (2021), no. 2, 599--610.
  6. DDAMULIRA, M., LUCA, F., AND RAKOTOMALALA, M., On a problem of Pillai with Fibonacci numbers and powers of 2, Proc. Indian Acad. Sci. Math. Sci. 127 (2017), no. 3, 411--421.
  7. DDAMULIRA, M., On the problem of Pillai with Padovan numbers and powers of 3, Studia Sci. Math. Hungar. 56 (2019), no. 3, 364--379.
  8. DUJELLA, A. AND PETHŐ, A., A generalization of a theorem of Baker and Davenport, Q. J. Math. 49 (1998), no. 195, 291--306.

Details

Primary Language

English

Subjects

Algebra and Number Theory

Journal Section

Research Article

Publication Date

October 18, 2026

Submission Date

September 21, 2026

Acceptance Date

October 18, 2026

Published in Issue

Year 2026 Volume: 12 Number: 1

APA
Çağman, A. (2026). NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS. Eastern Anatolian Journal of Science, 12(1), 32-36. https://izlik.org/JA28KC54MK
AMA
1.Çağman A. NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS. Eastern Anatolian Journal of Science. 2026;12(1):32-36. https://izlik.org/JA28KC54MK
Chicago
Çağman, Abdullah. 2026. “NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS”. Eastern Anatolian Journal of Science 12 (1): 32-36. https://izlik.org/JA28KC54MK.
EndNote
Çağman A (October 1, 2026) NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS. Eastern Anatolian Journal of Science 12 1 32–36.
IEEE
[1]A. Çağman, “NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS”, Eastern Anatolian Journal of Science, vol. 12, no. 1, pp. 32–36, Oct. 2026, [Online]. Available: https://izlik.org/JA28KC54MK
ISNAD
Çağman, Abdullah. “NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS”. Eastern Anatolian Journal of Science 12/1 (October 1, 2026): 32-36. https://izlik.org/JA28KC54MK.
JAMA
1.Çağman A. NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS. Eastern Anatolian Journal of Science. 2026;12:32–36.
MLA
Çağman, Abdullah. “NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS”. Eastern Anatolian Journal of Science, vol. 12, no. 1, Oct. 2026, pp. 32-36, https://izlik.org/JA28KC54MK.
Vancouver
1.Abdullah Çağman. NARAYANA’S COWS NUMBERS AS DIFFERENCES OF TWO PELL NUMBERS. Eastern Anatolian Journal of Science [Internet]. 2026 Oct. 1;12(1):32-6. Available from: https://izlik.org/JA28KC54MK