Strong pseudoprimes to twelve prime bases

  title={Strong pseudoprimes to twelve prime bases},
  author={J. Sorenson and Jonathan Webster},
  journal={Math. Comput.},
Let $\psi_m$ be the smallest strong pseudoprime to the first $m$ prime bases. This value is known for $1 \leq m \leq 11$. We extend this by finding $\psi_{12}$ and $\psi_{13}$. We also present an algorithm to find all integers $n\le B$ that are strong pseudoprimes to the first $m$ prime bases; with a reasonable heuristic assumption we can show that it takes at most $B^{2/3+o(1)}$ time. 

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