2025/04/26 by Batte, Herbert
#11B39 #11D45 #11D61 #11Y50 #FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.2504.19052
Let k ≥ 2 be an integer and consider the k-generalized Pell sequence \Pn(k)\n ≥ 2-k, defined by the initial values 0, …, 0, 0, 1 (a total of k terms), and the recurrence Pn(k) = 2Pn-1(k) + Pn-2(k) + ⋯ + Pn-k(k), for all n≥ 2. For any integer m, let P(m) denote the largest prime factor of m, with the convention P(0) = P(±1) = 1. In this paper, we prove that for n ≥ 4, the inequality P(Pn(k)) > (1/104) log log n holds. Additionally, we find all k-generalized Pell numbers Pn(k), whose largest prime factor does not exceed 7.