Take b = 2.

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

59 is prime.

b^((n-1)/59)-1 mod n = 3465, which is a unit, inverse 1179.

17 is prime.

b^((n-1)/17)-1 mod n = 4002, which is a unit, inverse 1824.

(17 * 59) divides n-1.

(17 * 59)^2 > n.

n is prime by Pocklington's theorem.