Primality proof for n = 308761441:
<p>Take b = 3.
<p>b^(n-1) mod n = 1.
<p><a href=49481.html>49481 is prime.</a>
<br>b^((n-1)/49481)-1 mod n = 201156782, which is a unit, inverse 43610143.
<p>(49481) divides n-1.
<p>(49481)^2 > n.
<p>n is prime by Pocklington's theorem.