2019/94/3-4 (15)
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DOI: 10.5486/PMD.2019.8433
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pp. 467-475
A generalization of Menon's identity to higher exponent
Abstract:
In this note, we shall explicitly compute the following sum
$$
\sum_{\substack{1\leq a,b_1,\dots,b_k\leq n\\\gcd(a,n)=1}}\operatorname{gcd}(a^\ell-1,b_1,\dots,b_k,n),
$$
where $n\geq 1$, $k\geq 0$, $l\geq 1$ are integers. Our results extend Menon's identity and Sury's identity (i.e., $\ell=1$ in the above summation) to higher exponents. Note that in the case $k=0$, some of our results are recovered by the results of [21].
Keywords: Menon's identity, Dirichlet character, Dirichlet convolution, divisor function, Euler's totient function, Chinese remainder theorem
Mathematics Subject Classification: 11A07, 11A25
