2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/172625This paper is concerned with the arithmetic of the elliptic K3 surface with configuration [1,1,1,12,3*]. We determine the newforms and zeta-functions associated to X and its twists. We verify conjectures of Tate and Shioda for the reductions of X at 2 and 3.12 pages, 2 figures; final version: two typos corrected, references updatedNumber TheoryAlgebraic Geometry11F23, 11G25, 11G40, 14G10; 14J27, 14J28text