Primality proof for n = 19301:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=193.html>193 is prime.</a>
<br>b^((n-1)/193)-1 mod n = 15758, which is a unit, inverse 17220.
<p>(193) divides n-1.
<p>(193)^2 > n.
<p>n is prime by Pocklington's theorem.