2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/129504We show that if A is a subset of {1, ..., n} such that it has no pairs of elements whose difference is equal to p-1 with p a prime number, then the size of A is O(n(loglog n)^(-clogloglogloglog n)) for some positive constant c.22 pagesNumber Theory11P55; 11B83text