My Coauthors

listed in alphabetical order of their last name:

1. Saralee Aursukaree

2. Bruce C. Berndt 

3. Montree Jaidee

4. Sutasinee Kawsumarng  

5. Narissara Khaochim 

6. Tammatada Khemaratchatakumthorn

7. Naruesorn Khuntijit

8. Narongkorn Kitnak

9. Florian Luca

10. Passawan Noppakaew

11. Kritkhajohn Onphaeng

12. Wachiraya Palatsang

13. Niphawan Phoopha 

14. Phakhinkorn Phunphayap

15. Bencharat Prempreesuk

16. Kota Saito

17. Suchat Samphavat 

18. Jeffrey Shallit

19. Nat Sothanaphan

20. Kittipong Subwattanachai

21. Patcharee Sumritnorrapong

22.  Laszlo Szalay 

23. Imchit Termwuttipong

24. Teraporn Thongsiri

25. Nattanard Triphop

26. Robert C. Vaughan 

27. Watcharakiete Wongcharoenbhorn

List of Publications (from the present back to 2012)

Accepted, submitted, or in preparation 

• P. Pongsriiam, Sums of divisors on arithmetic progressions, Periodica Mathematica Hungarica,  online first version https://doi.org/10.1007/s10998-023-00566-x

• P. Napp Phunphayap, T. Khemaratchatakumthorn, and P. Pongsriiam, Niven numbers and a unique property of 2023, accepted

• K. Onphaeng, P. Napp Phunphayap, T. Khemaratchatakumthorn, and P. Pongsriiam, Exact formulas for the number of palindromes in certain arithmetic progressions, Journal of Integer Sequences, 27(4) (2024), Article 24.4.8

• P. Napp Phunphayap, P. Noppakaew, and P. Pongsriiam, Directed graphs of integers with arcs determined by an arithmetic function, submitted

2023

• P. Napp Phunphayap and P. Pongsriiam, A complete comparison for the number of palindromes in different bases, AIMS Mathematics, 8(4) (2023), 9924--9932. 

• N. Phoopha, P. Pongsriiam, and P. Phunphayap, Digit Maps,  Mathematical Gazette, 107(568) (2023), 35-43

• P. Noppakaew and P. Pongsriiam, Product of some polynomials and arithmetic functions, Journal of Integer Sequences, 26(9) (2023), Article 23.9.1

• P. Pongsriiam and K. Saito, Palindromes and antipalindromes in short intervals, Journal of Integer Sequences, 26(9) (2023), Article 23.9.5

2022

• P. Napp Phunphayap and P. Pongsriiam, Extremal orders and races between palindromes in different bases, AIMS Mathematics, 7(2) (2022), 2237--2254. 

• P. Napp Phunphayap and P. Pongsriiam, Divisibility of Fibonomial coefficients in terms of their digital representations and applications, AIMS Mathematics, 7(4) (2022), 5314--5327.

• P. Napp Phunphayap, P. Pongsriiam, and J. Shallit, Sumsets associated with Beatty sequences, Discrete Mathematics, 345(5) (2022), Article 112810.

• P. Pongsriiam, Combinatorial structure and sumsets associated with Beatty sequences generated by powers of the golden ratio, Electronic Research Archive, 30(7) (2022), 2385--2405. 

• P. Napp Phunphayap, T. Khemaratchatakumthorn, N. Sothanaphan, K. Onphaeng, W. Wongcharoenbhorn, P. Sumritnorrapong, and P. Pongsriiam, Combinatorial inequalities arising from the inclusion-exclusion principle, Journal of Mathematical Inequalities,16(4) (2022), 1455-1475.

2021

• P. Pongsriiam, Quasi-injectivity of some arithmetic functions, Journal of Integer Sequences, 24(10) (2021), Article 21.10.1, 1--13.

• P. Pongsriiam and K. Subwattanachai, Arithmetic progressions in the values of a quadratic polynomial, the American Mathematical Monthly, 128(10) (2021), 937--941

• Pongsriiam and R. C. Vaughan, The divisor function on residue classes III, The Ramanujan Journal, 56(2) (2021), 697--719.

• W. Palatsang, P. Pongsriiam, T. Khemaratchatakumthorn, K. Subwattanachai, N. Khuntijit, N. Kitnak, Remarks on certain sums involving the floor function, ScienceAsia, 47(5)(2021), 640--644

• K. Onphaeng and P. Pongsriiam, Exact divisibility by powers of the integers in the Lucas sequences of the first and second kinds, AIMS Mathematics, 6(11) (2021), 11733--11748. 

• P. Pongsriiam, Longest arithmetic progressions of palindromes, Journal of Number Theory,  222 (2021), 362--375. 

• N. Phoopha and P. Pongsriiam, Notes on $1089$ and a variation of the Kaprekar operator, International Journal of Mathematics and Computer Science, 16(4) (2021), 1599--1606.

• S. Aursukaree and P. Pongsriiam, On exactly 3--deficient--perfect numbers, The Fibonacci Quarterly, 59(1) (2021), 33--46. 

• F. Luca, P. Pongsriiam, and L. Szalay, On the divisibility $F_k\mid F_x^2+F_x+1$, ScienceAsia, 47(1) (2021), 106--110.

• S. Kawsumarng, T. Khemaratchatakumthorn, P. Noppakaew, and P. Pongsriiam, Sumsets associated with Wythoff sequences and Fibonacci numbers, Periodica Mathematica Hungarica, 82(1) (2021), 98--113.

• K. Subwattanachai and P. Pongsriiam, Composition of happy functions and digit maps, International Journal of Mathematics and Computer Science, 16(1) (2021), 169--178.

2020

• P. Pongsriiam, Fibonacci and Lucas numbers associated with Brocard-Ramanujan equation II, Mathematical Reports, 22(72) (2020), 213--231. 

• S. Samphavat, T. Khemaratchatakumthorn, and P. Pongsriiam, Remarks on b-metrics, ultrametrics, and metric-preserving functions, Mathematica Slovaca, 70(1) (2020), 61--70. 

• B. Prempreesuk, P. Noppakaew, and P. Pongsriiam, Zeckendorf representation and multiplicative inverse of $ F_m \bmod F_n$, International Journal of Mathematics and Computer Science, 15(1) (2020), 17--25.

• P. Phunphayap and P. Pongsriiam, Explicit formulas for the p-adic valuations of Fibonomial coefficients II, AIMS Mathematics, 5(6) (2020), 5685--5699. 

• K. Onphaeng and P. Pongsriiam, Exact divisibility by powers of the integers in the Lucas sequence of the first kind, AIMS Mathematics, 5(6) (2020), 6739--6748. 

• S. Kawsumarng, T. Khemaratchatakumthorn, P. Noppakaew, and P. Pongsriiam, Distribution of Wythoff sequences modulo one, International Journal of Mathematics and Computer Science, 15(4) (2020), 1045--1053.

2019

• P. Phunphayap and P. Pongsriiam, Reciprocal sum of palindromes, Journal of Integer Sequences, 22(8) (2019), Article 19.8.6, 1--13.

• P. Pongsriiam, Fibonacci and Lucas numbers which have exactly three prime factors and some unique properties of $F_{18}$ and $L_{18}$, Fibonacci Quarterly, 57(5) (2019), 130--144. 

• P. Pongsriiam, The order of appearance of factorials in the Fibonacci sequence and certain Diophantine equations, Periodica Mathematica Hungarica, 79(2) (2019), 141--156.

• P. Noppakeaw, N. Phoopha, and P. Pongsriiam, Composition of happy functions, Notes on Number Theory and Discrete Mathematics, 25(3) (2019), 13--20. 

• M. Jaidee and P. Pongsriiam, Arithmetic functions of Fibonacci and Lucas numbers, Fibonacci Quarterly, 57(3) (2019), 246--254. 

• S. Aursukaree, T. Khemaratchatakumthorn, and P. Pongsriiam, Generalizations of Hermite's identity and applications, Fibonacci Quarterly, 57(2) (2019), 126--133. Corrigendum in Fibonacci Quarterly, 58(1) (2020), 80--80.

• T. Khemaratchatakumthorn, P. Pongsriiam, and S. Samphavat, Further remarks on b--metrics, metric--preserving functions, and other related metrics, International Journal of Mathematics and Computer Science, 14(2) (2019), 473--480.

• P. Pongsriiam and K. Subwattanachai, Exact formulas for the number of palindromes up to a given positive integer, International Journal of Mathematics and Computer Science, 14(1) (2019), 27--46.

2018

• B. Prempreesuk, P. Pongsriiam, and N. Kanyamee, Numerical methods for finding multiplicative inverses of a modulo N, Songklanakarin Journal of Science and Technology, 40(6) (2018), pp. 1361--1367.

• N. Khaochim and P. Pongsriiam, On the order of appearance of products of Fibonacci numbers, Contributions to Discrete Mathematics, 13(2) (2018), pp. 45--62.

• K. Onphaeng and P. Pongsriiam, The converse of exact divisibility by powers of the Fibonacci and Lucas numbers, Fibonacci Quarterly, 56(4) (2018), pp. 296--302.

• T. Khemaratchatakumthorn and P. Pongsriiam, Remarks on b-metric and metric-preserving functions, Mathematica Slovaca, 68(5) (2018), pp. 1009--1016.  

• Khaochim and P. Pongsriiam, The general case on the order of appearance of product of consecutive Lucas numbers, Acta Mathematica Universitatis Comenianae, 87(2) (2018), pp. 277--289.

• P. Phunphayap and P. Pongsriiam, Explicit formulas for the p-adic valuations of Fibonomial coefficients, Journal of Integer Sequences, 21(3) (2018), Article 18.3.1.

• Pongsriiam and R. C. Vaughan, The divisor function on residue classes II, Acta Arithmetica, 182(2) (2018), pp.133--181.

• P. Pongsriiam, Longest arithmetic progressions in reduced residue systems, Journal of Number Theory, 183 (2018), pp. 309--325.

2017

• Pongsriiam, Fibonacci and Lucas numbers associated with Brocard-Ramanujan equation, Communications of the Korean Mathematical Society, 32(3) (2017), pp. 511--522.

• P. Pongsriiam, Integral values of the generating functions of Fibonacci and Lucas numbers, College Mathematics Journal, 48(2) (2017), pp. 97--101.

• K. Onphaeng and P. Pongsriiam, Jacobsthal and Jacobsthal-Lucas numbers and sums introduced by Jacobsthal and Tverberg, Journal of Integer Sequences, 20(3) (2017), Article 17.3.6. Link 

• P. Pongsriiam, Fibonacci and Lucas Numbers which are one away from their products, Fibonacci Quarterly 55(1) (2017), pp. 29--40.

2016

• P. Pongsriiam, Factorization of Fibonacci numbers into products of Lucas numbers and related results, JP Journal of Algebra, Number Theory and Applications, 38(4) (2016), pp. 363--372.

• P. Pongsriiam, A complete formula for the order of appearance of the powers of Lucas numbers, Communications of the Korean Mathematical Society, 31(3) (2016), pp. 447--450.

• P. Pongsriiam, Local behaviors of the number of relatively prime sets, International Journal of Number Theory, 12(6) (2016), pp. 1575--1593.

• T. Khemaratchatakumthorn and P. Pongsriiam, Remarks on uniformly symmetrically continuous functions, Asian-European Journal of Mathematics, 9(3) (2016), Article Number 1650069.

• P. Pongsriiam and T. Thongsiri, Weakly symmetrically continuous function, Chamchuri Journal of Mathematics, 8 (2016), pp. 49--65.

2015

• P. Pongsriiam and R. C. Vaughan, The divisor function on residue classes I, Acta Arithmetica, 168(4) (2015), pp. 369--381.

• P. Pongsriiam, The product of n distinct derivatives, American Mathematical Monthly, 122(9) (2015), 906--906. Link 

2012--2014

• P. Pongsriiam, Exact divisibility by powers of the Fibonacci and Lucas numbers, Journal of Integer Sequences, 17(11) (2014), Article 14.11.2, 1-12. 

• P. Pongsriiam and I. Termwuttipong, On metric-preserving functions and fixed point theorems, Fixed Point Theory and Applications 2014, 2014:179, 1--14.

• P. Pongsriiam and I. Termwuttipong, Remarks on ultrametrics and metric-preserving functions, Abstract and Applied Analysis, 2014, Article Number 163258, 1--9.

• K. Onphaeng and P. Pongsriiam, Subsequences and divisibility by powers of the Fibonacci numbers, The Fibonacci Quarterly, 52(2) (2014), 163--171.

• N. Khaochim and P. Pongsriiam, The period modulo product of consecutive Fibonacci numbers, International Journal of Pure and Applied Mathematics, 90(3) (2014), 335--344.

• P. Pongsriiam, Relatively prime sets, divisor sums, and partial sums, Journal of Integer Sequences, 16(9) (2013), Article 13.9.1, 1--11. 

• P. Pongsriiam, A remark on relatively prime sets, Integers, 13(2013), A49, 14 pages. Also in P. Pongsriiam, A remark on relatively prime sets, Integers, Walter de Gruyter, Annual Volume 2013, (2014), 714--727.

• B. Berndt and P. Pongsriiam, Discarded fragments from Ramanujan's papers, Analytic and Probabilistic Methods in Number Theory, Kubilius Memorial Volume, 2012, 49--59.

List of Publications arranged according to topics ( under construction)

Problems in the divisors 

1. P. Pongsriiam and R. C. Vaughan, The divisor function on residue classes I, Acta Arithmetica, 168(4) (2015), 369--381. LinktoRG LinktoFinalVersion  

2. P. Pongsriiam and R. C. Vaughan, The divisor function on residue classes II, Acta Arithmetica, 182(2) (2018), 133--181. LinktoRG LinktoFinalVersion

3. P. Pongsriiam and R. C. Vaughan, The divisor function on residue classes III, The Ramanujan Journal, online first version 

4. P. Pongsriiam. Sums of divisors on arithmetic progressions, submitted

For more articles and information on this project, please follow the link Link to the project on the divisor functions and other arithmetic functions 

Arithmetic progressions in various integer sequences

5. P. Pongsriiam, Longest arithmetic progressions in reduced residue systems, Journal of Number Theory, 183 (2018), 309--325.     LinktoFinalVersion

6. P. Pongsriiam, Longest arithmetic progressions of palindromes, Journal of Number Theory, 222 (2021), 362--375. 

For more articles and information on this project, please follow the link Link to the project on long arithmetic progressions in various integer sequences 

Problems in Beatty sequences

7. S. Kawsumarng, T. Khemaratchatakumthorn, P. Noppakaew, and P. Pongsriiam, Sumsets associated with Wythoff sequences and Fibonacci numbers, Periodica Mathematica Hungarica, 82(1) (2021), 98--113.

For more articles and information on this project, please follow the link Problems in Beatty sequences 

Palindromes

8. P. Phunphayap and P. Pongsriiam, Reciprocal sum of palindromes, Journal of Integer Sequences, 22(8) (2019), Article 19.8.6, 1--13.  LinktoRG LinktoFinalVersion

For more articles and information on this project, please follow the link Problems in palindromes 

Sums and various properties of the floor function 

9. K. Onphaeng and P. Pongsriiam, Jacobsthal and Jacobsthal-Lucas numbers and sums introduced by Jacobsthal and Tverberg, Journal of Integer Sequences, 20(3) (2017), Article 17.3.6, 1--20.   LinktoRG LinktoFinalVersion

For more articles and information on this project, please follow the link Sums and inequalities involving the floor function  

Fibonacci numbers, the order of appearance, Fibonomial coefficients,  and generalizations

10. P. Phunphayap and P. Pongsriiam, Explicit formulas for the $p$-adic valuations of Fibonomial coefficients, Journal of Integer Sequences, 21(3) (2018), Article 18.3.1, 1--33.  LinktoRG LinktoFinalVersion

11. P. Pongsriiam, Fibonacci and Lucas numbers which have exactly three prime factors and some unique properties of $F_{18}$ and $L_{18}$, Fibonacci Quarterly, 57(5) (2019), 130--144. LinktoRG LinktoFinalVersion

12. P. Pongsriiam, The order of appearance of factorials in the Fibonacci sequence and certain Diophantine equations, Periodica Mathematica Hungarica, 79(2) (2019), 141--156. LinktoFinalVersion

13. K. Onphaeng and P. Pongsriiam, Exact divisibility by powers of the integers in the Lucas sequence of the first kind, AIMS Mathematics, 5(6) (2020), 6739--6748. 

For more articles and information on this project, please follow the link Fibonacci numbers, the order of appearance, Fibonomial coefficients, and generalizations  

Metric preserving functions 

14. P. Pongsriiam and I. Termwuttipong, Remarks on ultrametrics and metric--preserving functions, Abstract and Applied Analysis, 2014, Article Number 163258, 1--10.  LinktoRG  LinktoFinalVersion

15. T. Khemaratchatakumthorn and P. Pongsriiam, Remarks on b-metric and metric-preserving functions, Mathematica Slovaca, 68(5) (2018), 1009--1016.  LinktoFinalVersion 

16. T. Khemaratchatakumthorn, P. Pongsriiam, and S. Samphavat, Further remarks on b--metrics, metric--preserving functions, and other related metrics, International Journal of Mathematics and Computer Science, 14(2) (2019), 473--480.   LinktoFinalVersion  

17. S. Samphavat, T. Khemaratchatakumthorn, and P. Pongsriiam, Remarks on b-metrics, ultrametrics, and metric-preserving functions, Mathematica Slovaca, 70(1) (2020), 61--70.  LinktoFinalVersion 

For more articles and information on this project, please follow the link Metric-preserving functions 

Miscellaneous problems

18. P. Pongsriiam, Local behaviors of the number of relatively prime sets, International Journal of Number Theory, 12(6) (2016), 1575--1593.  LinktoRG LinktoFinalVersion