Primality proof for n = 7583:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=223.html>223 is prime.</a>
<br>b^((n-1)/223)-1 mod n = 6375, which is a unit, inverse 747.
<p>(223) divides n-1.
<p>(223)^2 > n.
<p>n is prime by Pocklington's theorem.