A computer in Missouri has discovered the largest known prime number, 2^{74,207,281}– 1. It is about 22 million digits long, 5 million digits longer than the previous largest known prime, which was discovered in January 2013.

Prime numbers are numbers that are divisible only by themselves and one, such as 2, 3, 5, 7, 11 and 13. The search for the highest known prime is a long-established mathematical quest, of interest now more as a test of computing power rather than for any practical use of the number itself. It’s a fun challenge too.

Primes that can be written as one less than a power of two, i.e 2^{n} – 1 for some *n*, are known as Mersenne primes after the French monk Marin Mersenne who investigated their properties 350 years ago. They are the easiest large primes to find since they provide numbers to aim for, and there’s a quick way to test they are prime.

**@ THE GUARDIAN**

## About Den

Always in search of interesting things to post.
Armed with knowledge and dangerous with the ladies.

That’s different than prime rib.

Just across Stadium Way the former church lot is being turned into deluxe townhouses. The units are 4 bedroom with 4.5 baths. There will be 2 triplexs.

Sunny today so I’ll go stick walking.

The Upper-Crusties, coming to a neighborhood near you.

Yes, for the sort of student who drives a new Cadillac.

@ the Hillside Cafe after a nominal 15 minutes on the sticks. I hit a wrong button on the mobile device and erased the timer. Don’t think there is a history feature.

Actually I just shifted it over to the timer feature; indeed it was 15+ minutes.

Then over the top of the hill by the CUB and thence east along Grimes Way. The research building is finished. It looks better than most of the newer buildings out that way. A bit further on, in front of the Grimes Way steam plant, the new protective services building is under construction.

Thence south to the Moscow highway, across it to Chipman Trail, generally west along the trail to Benewah Street, south a short way to the Birch & Barley. 70 minutes.

I’m having a black IPA. Wow.

Thence past the COmmunity Gadens and the Koppel Farm, where I used to go to buy milk decades ago, along the Riverwalk to the p.stairs and thence to Sloan. An actually measured 28 minutes, which is longer than I had been assuming. For today, 15+70+28=113 minutes.

Day 5: 62+113=175 minutes, more than the desired minimum for the week. That doesn’t mean I’ll not try to do more, depending upon the weather.

Oh yes, even through it is still January, the skunk cabbage is up.

Meanwhile back in the slum, diesels prevail along with the idiots that own them.

Still no luck locating new quarters, house prices are climbing into the sky, $80K for a mobile home built in the 70’s in a park with lot rents $500 and up are the most ridiculous, houses that are basically teardowns are asking $170K. I qualify for $100K. I might be really stuck here in the slum.

My bones are rallying against me lately too. Hope is dwindling.

😦

Oh,

Carol, I did finally get your card, thanks!My bedroom on wheels.

Maybe I’ll hire out as a Gigolo.

🙂

Just walked home, right foot noticeable after such a long stick walk following a weather required layoff.

Planet 9 is out there somewhere, they know it, one problem,

no one has actually seen it.

Seems unlikely.

Comes from CalTech so maybe so.