Primality proof for n = 2531:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=23.html>23 is prime.</a>
<br>b^((n-1)/23)-1 mod n = 216, which is a unit, inverse 996.
<p><a href=11.html>11 is prime.</a>
<br>b^((n-1)/11)-1 mod n = 1054, which is a unit, inverse 1083.
<p>(11 * 23) divides n-1.
<p>(11 * 23)^2 > n.
<p>n is prime by Pocklington's theorem.