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Aug 18, 2020 at 2:18 comment added Chua KS It seems useful to state many of your tests in term of Chebyshev.Eg. Lucas-Lehmer for Mersenne prime $M_p=2^p-1$ can be rephrased as $M_p$ is prime iff $T_{2^{p-2}}(2)=0$ mod $M_p$ and the Chebyshev rule $T_m(T_n(x))=T_{mn}(x)$ implied many possible method for computing the residue. Since $2^{p-2}=4^{(p-3)/2}.2$, one can iterate with $T_4$ as $T_{2^{p-2}}(2)=T_4^{(p-3)/2}(T_2(2))$ mod $M_p$. This halfed the number of steps but evaluating $T_4$ is more expansive. Every partition of $p-2$ into positive parts give a different way to compute the residue. At least good for checking correctness
Aug 15, 2020 at 4:48 comment added Chua KS $P_m(x)=2T_m(x/2)$ where $T_m(x)$ is the Chebyshev polynomial of the first kind. The claim can be rephrased as $F_{p,n}$ is prime iff $T_{2^{2^n-2}p^{2^n}}(4)=0$ mod $F_{p,n}$. Since $T_m(T_n(x))=T_{mn}(x)$, the RHS can be computed efficiently as $T_{ (2p)}^{2^n-2}(T_{p^2}(4))$ mod $F_{p,n}$, where the $2^n-2$ in the power means iteration.
Aug 13, 2020 at 3:50 history edited Pedja CC BY-SA 4.0
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Apr 24, 2018 at 21:46 comment added Steven Stadnicki It might be worth noting that the $P_m$ satisfy a particularly straightforward linear recurrence.
Apr 24, 2018 at 19:00 history edited Pedja CC BY-SA 3.0
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Apr 22, 2018 at 13:43 comment added Pedja @MaxAlekseyev Actually this is a generalization of Inkeri's primality test for Fermat numbers...Reference : Tests for primality, Ann. Acad. Sci. Fenn. Ser. A I 279 (1960), 1-19.
Apr 22, 2018 at 13:09 comment added Max Alekseyev Looks like a generalization of arxiv.org/abs/0705.3664 (which concerns $b=2$)
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