Primality proof for n = 2683:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=149.html>149 is prime.</a>
<br>b^((n-1)/149)-1 mod n = 1892, which is a unit, inverse 251.
<p>(149) divides n-1.
<p>(149)^2 > n.
<p>n is prime by Pocklington's theorem.