Take b = 2.

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

37 is prime.

b^((n-1)/37)-1 mod n = 2994, which is a unit, inverse 2135.

2 is prime.

b^((n-1)/2)-1 mod n = 3329, which is a unit, inverse 1665.

(2 * 37) divides n-1.

(2 * 37)^2 > n.

n is prime by Pocklington's theorem.