Strong pseudoprime
= Strong pseudoprime
{wiki}
Write the even number $N-1$ as $2^s m$ with $m$ odd. An odd composite number $N$ is a strong pseudoprime to a coprime base $b$ when
$$
b^m\equiv1\pmod N
$$
or $b^{2^jm}\equiv-1\pmod N$ for some $0\leq j<s$.