Primality proof for n = 37967:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=463.html>463 is prime.</a>
<br>b^((n-1)/463)-1 mod n = 17755, which is a unit, inverse 30797.
<p>(463) divides n-1.
<p>(463)^2 > n.
<p>n is prime by Pocklington's theorem.