Primality proof for n = 479:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=239.html>239 is prime.</a>
<br>b^((n-1)/239)-1 mod n = 3, which is a unit, inverse 160.
<p>(239) divides n-1.
<p>(239)^2 > n.
<p>n is prime by Pocklington's theorem.