A scaling property of Farey fractions. Part IV: mean value formulas

The Farey sequence of order n consists of all reduced fractions a / b between 0 and 1 with positive denominator b less or equal to n. In a series of former papers we obtained a limit function which describes a scaling property of the Farey sequence of order n for $$n \rightarrow \infty $$ in the vicinity of any fixed fraction a / b and which is independent of a / b. In this paper we derive a representation formula for a sequence of functions used in the Franel–Landau theorem to determine the number of Farey-fractions in prescribed intervals, and we establish a corresponding limit function for this sequence as well. This is combined with a former result to derive a remarkable representation formula for arithmetic means of related functions.