2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67807A first encounter with $A(λ) := \int_0^{+\infty}\{λt\}\{t\}t^{-2}dt.$ This text contains the detailed calculations leading to the results of our paper "Etude de l'autocorrelation multiplicative de la fonction "partie fractionnaire"", to appear in the Ramanujan Journal.45 pages, 1 figureNumber Theory11M26text