Take b = 2.

b^(n-1) mod n = 1.

383 is prime.

b^((n-1)/383)-1 mod n = 201106, which is a unit, inverse 44600.

17 is prime.

b^((n-1)/17)-1 mod n = 234875, which is a unit, inverse 11603.

(17 * 383) divides n-1.

(17 * 383)^2 > n.

n is prime by Pocklington's theorem.