Abstract
Let d be a fixed positive integer. A Lucas d-pseudoprime is a Lucas pseudoprime N for which there exists a Lucas sequence U(P, Q) such that the rank of N in U(P, Q) is exactly (N − ε(N))/d, where ε is the signature of U(P, Q). We prove here that all but a finite number of Lucas d-pseudoprimes are square free. We also prove that all but a finite number of Lucas d-pseudoprimes are Carmichael-Lucas numbers.
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Carlip, W., Somer, L. Square-free Lucas d-pseudoprimes and Carmichael-Lucas numbers. Czech Math J 57, 447–463 (2007). https://doi.org/10.1007/s10587-007-0072-6
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DOI: https://doi.org/10.1007/s10587-007-0072-6