In mathematics, in particular number theory, an odd composite number N is a Somer–Lucas d-pseudoprime (with given d ≥ 1) if there exists a nondegenerate Lucas sequence with the discriminant such that and the rank appearance of N in the sequence U(P, Q) is
where is the Jacobi symbol.
Unlike the standard Lucas pseudoprimes, there is no known efficient primality test using the Lucas d-pseudoprimes. Hence they are not generally used for computation.
Lawrence Somer, in his 1985 thesis, also defined the Somer d-pseudoprimes. They are described in brief on page 117 of Ribenbaum 1996.
- Somer, Lawrence (1998). Bergum, Gerald E.; Philippou, Andreas N.; Horadam, A. F., eds. "On Lucas d-Pseudoprimes". Applications of Fibonacci Numbers (Springer Netherlands) 7: 369–375. doi:10.1007/978-94-011-5020-0_41.
- Carlip, Walter; Somer, Lawrence (2007). "Square-free Lucas d-pseudoprimes and Carmichael-Lucas numbers". Czechoslovak Mathematical Journal 57 (1).
- Weisstein, Eric W., "Somer–Lucas Pseudoprime", MathWorld.
- Ribenboim, P. (1996). "§2.X.D Somer-Lucas Pseudoprimes". The New Book of Prime Number Records (3rd ed. ed.). New York: Springer-Verlag. pp. 131–132.