Primality proof for n = 326257:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=971.html>971 is prime.</a>
<br>b^((n-1)/971)-1 mod n = 244380, which is a unit, inverse 102754.
<p>(971) divides n-1.
<p>(971)^2 > n.
<p>n is prime by Pocklington's theorem.