Samia, ZikemFatima Zohra, SayhiSupervisor: Abdelmajid, Boudaoud2025-07-072025-07-072025-06-15https://repository.univ-msila.dz/handle/123456789/46715In this work, we consider the linear recurrent sequences with constant coefficients of order 2, focusing on those defining Pell and Pell-Lucas numbers. In this context, we have examined the corresponding Binet formulas and the possibilities for a Pell or Pell-Lucas number to become a member of another family such as the families of triangular, pentagonal, heptagonal numbers, ... . We also reviewed some identities linking these numbers, and finished our work with some formulas involving the sum and multiplication of these numbers.enPell numberPell-Lucas numberBinet formulasIdentityThesis