Mersenne primes, you'll recall, are those in the form (2^p) - 1, where p is itself prime.

When p=2, you get 2^2 - 1 = 3, which is prime

When p=3, you get 2^3 - 1 = 7, which is prime

When p=5, you get 2^5 - 1 = 31, which is prime

When p=7, you get 2^7 - 1 = 127, which is prime

Seems like a pattern is forming, but with p=11, you get 2047, which is obviously 23 x 89, i.e. not a prime.

This new prime is only the 46th Mersenne prime known. I would be hard-pressed to show that 43,112,609 is prime, but this new one is 2^43,112,609 - 1, a number with nearly 13 million digits.

Oktoberfest in Munich seems to be changing for the better, as if that were possible.

Speaking of which, Chalet Edelweiss now seems to be open for business, although there's still some odd construction material about. The menu doesn't thrill me, but German beer on tap calls to me.