On the power-free parts of consecutive integers
We show that is powerfull for integers at most, thus answering a question of P. Ribenboim.
Let be a fixed integer. We study the asymptotic formula of , which is the number of positive integer solutions such that the polynomial is -free. We obtained the asymptotic formula of for all . Our result is new even in the case . We proved that , where is a constant depending on . This improves upon the error term obtained by G.-L. Zhou, Y. Ding (2022).
Let λ denote Carmichael’s function, so λ(n) is the universal exponent for the multiplicative group modulo n. It is closely related to Euler’s φ-function, but we show here that the image of λ is much denser than the image of φ. In particular the number of λ-values to x exceeds for all large x, while for φ it is equal to , an old result of Erdős. We also improve on an earlier result of the first author and Friedlander giving an upper bound for the distribution of λ-values.