[genius] Update primes

[George Lebl <jirka src gnome org>]

commit e229bd9d5c49a5ec69a6266388deb21fce41c7f3
Author: Jiri (George) Lebl <jiri lebl gmail com>
Date:   Sat Apr 7 20:25:45 2018 -0500

    Update primes

 lib/number_theory/primes.gel |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/lib/number_theory/primes.gel b/lib/number_theory/primes.gel
index ae9d20a..e436b69 100644
--- a/lib/number_theory/primes.gel
+++ b/lib/number_theory/primes.gel
@@ -123,10 +123,10 @@ function IsMersennePrimeExponent(p) = (
                return true;
 
        # http://www.mersenne.org / GIMPS doublechecked everything up
-       # to 42 120 083 (on Jan 12, 2018)
-       if p < 42120083 then
+       # to 42 866 599 (on Apr 7, 2018)
+       if p < 42866599 then
                return false;
 
-       error("IsMersennePrimeExponent: Number too large (known values up to: " + 42120083 + ")");
+       error("IsMersennePrimeExponent: Number too large (known values up to: " + 42866599 + ")");
        bailout
 );