Primality proof for n = 121283:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=8663.html>8663 is prime.</a>
<br>b^((n-1)/8663)-1 mod n = 16383, which is a unit, inverse 17397.
<p>(8663) divides n-1.
<p>(8663)^2 > n.
<p>n is prime by Pocklington's theorem.