Abstract :
Forf(X)set membership, variantimage[X], letDf(n) be the least positive integerkfor whichf(1), …, f(n) are distinct modulok. Several results have been proven about the functionDfin recent years, culminating in Moreeʹs characterization ofDf(n) wheneverflies in a certain (large) subset of image[X] andnis sufficiently large. We give several improvements of Moreeʹs result, as well as further results on the functionDf.
