@Article{LanguascoZaccagnini2013a, Author = "A. Languasco and A. Zaccagnini", Title = "A {Ces\`aro} average of {Hardy}-{Littlewood} numbers", Journal = "J. Math. Anal. Appl.", Volume = 401, Pages = "568--577", Url = "\url{http://dx.doi.org/10.1016/j.jmaa.2012.12.046}", Year = 2013, Abstract = "We study averages of the quantity $R_{\textit{HL}}(n) = \sum_{m_1 + m_2^2 = n} \Lambda(m_1)$. In particular, for any $k > 1$ we give an ``explicit formula'' for \[ \sum_{n \le N} R_{\textit{HL}}(n) \frac{(1 - n / N)^k}{\Gamma(k + 1)} \] in terms of the Gamma function evaluated at suitable combinations of the Riemann zeta-function, and of Bessel functions of complex order." }