Primality proof for n = 2237:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=43.html>43 is prime.</a>
<br>b^((n-1)/43)-1 mod n = 1983, which is a unit, inverse 502.
<p><a href=13.html>13 is prime.</a>
<br>b^((n-1)/13)-1 mod n = 213, which is a unit, inverse 2216.
<p>(13 * 43) divides n-1.
<p>(13 * 43)^2 > n.
<p>n is prime by Pocklington's theorem.