Primality proof for n = 411743:
Take b = 2.
b^(n-1) mod n = 1.
229 is prime.
b^((n-1)/229)-1 mod n = 810, which is a unit, inverse 372602.
31 is prime.
b^((n-1)/31)-1 mod n = 207456, which is a unit, inverse 366398.
(31 * 229) divides n-1.
(31 * 229)^2 > n.
n is prime by Pocklington's theorem.