the two most cited composites are pmod and acrim.
the two most cited composites are pmod and acrim.
catalan pseudoprime:0
in mathematics, a catalan pseudoprime is an odd composite number n satisfying the congruence ( − 1 ) n − 1 2 ⋅ c n − 1 2 ≡ 2 ( mod n ) , {\displaystyle (-1)^{\frac {n-1}{2}}\cdot c_{\frac {n-1}{2}}\equiv 2{\pmod {n}},} where cm denotes the m-th catalan number.