Primality proof for n = 4283:

Take b = 2.

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

2141 is prime.
b^((n-1)/2141)-1 mod n = 3, which is a unit, inverse 1428.

(2141) divides n-1.

(2141)^2 > n.

n is prime by Pocklington's theorem.