Primality proof for n = 490949:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=883.html>883 is prime.</a>
<br>b^((n-1)/883)-1 mod n = 124238, which is a unit, inverse 224088.
<p>(883) divides n-1.
<p>(883)^2 > n.
<p>n is prime by Pocklington's theorem.