“…It is important to emphasize again how these topics and techniques can be related to other, and sometimes unexpected, mathematical topics; for example, if it is quite natural to think about the classical Ramanujan-type series for 1/π (for a survey of this topic, see, for example, [3] and for formulas via hypergeometric transformations see [15]), the connection with additive number theory problems is probably less evident. Indeed, fractional operators applied to particular power series are involved in the study of explicit formulas for the so-called Cesaro average that counts the number of representations of an integer as sums of primes, prime powers, and squares of integers (for the interested reader, see [7,[11][12][13]20]); therefore, it is plausible to think that the techniques developed may also be of interest for these types of problems In this paper, we will focus on a results of Zhou [21] about a closed form for the generalized Clebsch-Gordan integral 1 −1 P μ (x) P ν (x) P ν (−x) dx, where P ν (x) , P μ (x) are the Legendre functions of arbitrary complex degree ν, μ ∈ C. We show that this result can be can be interpreted in terms of the FL theory and this point of view allows to evaluate series in which addends are powers of central binomials (and so, particular hypergeometric functions). Furthermore, we will show that from Zhou's results, we can obtain some formulas that recall the well-known Brafman's formula [6] and we can evaluate very easily some integral moments involving combinations of complete elliptic integrals of the first kind.…”