Fermatian | Sarrus number

A Poulet number is a Fermat pseudoprime to base 2, denoted psp(2), i.e., a composite number n such that 2^(n - 1) congruent 1 (mod n). The first few Poulet numbers are 341, 561, 645, 1105, 1387, ... (OEIS A001567). Pomerance et al. (1980) computed all 21853 Poulet numbers less than 25×10^9. The numbers less than 10^2, 10^3, ..., are 0, 3, 22, 78, 245, ... (OEIS A055550).

Fermat pseudoprime | pseudoprime | Rotkiewicz theorem | super-Poulet number