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Multiplicative independence in the sequence of $k$-generalized Pell numbers

Number Theory 2026-05-19 v1

Abstract

We study multiplicative dependence between terms of the kk-generalized Pell sequence (Pn(k))n2k(P_n^{(k)})_{n\ge 2-k}, defined by the linear recurrence Pn(k)=2Pn1(k)+Pn2(k)++Pnk(k), P_n^{(k)} = 2P_{n-1}^{(k)} + P_{n-2}^{(k)} + \dots + P_{n-k}^{(k)}, with initial conditions P0(k)==P(k2)(k)=0P_0^{(k)} = \dots = P_{-(k-2)}^{(k)} = 0 and P1(k)=1P_1^{(k)} = 1. For k2k\ge 2 we determine all pairs (m,n)(m,n) with n>m0n>m\ge 0 such that Pn(k)P_n^{(k)} and Pm(k)P_m^{(k)} are multiplicatively dependent. The main result states that the only solutions occur for very small k,m,nk,m,n (which are listed explicitly). The proof uses lower bounds for linear forms in logarithms (Matveev), the Baker-Davenport reduction algorithm, and a computational search.

Keywords

Cite

@article{arxiv.2605.17699,
  title  = {Multiplicative independence in the sequence of $k$-generalized Pell numbers},
  author = {Cherif B. Deme and Kancou D. Fall and Khady Faye and Bernadette Faye},
  journal= {arXiv preprint arXiv:2605.17699},
  year   = {2026}
}

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11 pages