On members of Lucas sequences which are either products of factorials or product of middle binomial coefficients and Catalan numbers

Research in Number Theory - Tập 7 - Trang 1-24 - 2021
Shanta Laishram1
1Stat-Math Unit, Indian Statistical Institute, New Delhi, India

Tóm tắt

Let $$\{U_n\}_{n\ge 0}$$ be a Lucas sequence. We show that if $$U_n$$ is a product of factorials, then $$n\in \{1,2, 3, 4, 6, 8, 12\}$$ . Further we show that if $$U_n$$ is a product of Catalan numbers or the middle binomial coefficients, then $$n\in \{1,2, 3, 4, 6, 8, 12, 16\}$$ . Here the $$m-$$ th middle binomial coefficient is $$B_m=\left( {\begin{array}{c}2m\\ m\end{array}}\right) $$ and the $$m-$$ th Catalan number is $$C_m=\frac{1}{m+1}\left( {\begin{array}{c}2m\\ m\end{array}}\right) $$ .

Tài liệu tham khảo

Bilu, Y., Hanrot, G., Voutier, P.M.: Existence of primitive divisors of Lucas and Lehmer numbers, with an appendix by M. Mignotte. J. Reine Angew. Math. 539, 75–122 (2001) Laishram, S., Luca, F., Sias, M.: On members of Lucas sequences which are products of factorials. Monatsh. Math. 193, 329–359 (2020) Laishram, S., Luca, F., Sias, M.: On members of Lucas sequences which are products of Catalan numbers. Int. J. Number Theory. (2021). https://doi.org/10.1142/S1793042121500457