# University of California, Los Angeles

The **University of California, Los Angeles (UCLA)** is the largest of the University of California campuses (by enrollment). It is situated in the Westwood area of Los Angeles. It has a long history in the fields of mathematics and computer science. UCLA was the **first** host on the **Internet** in 1969 (back when it was known as ARPAnet). This ushered in the modern era of connectivity and led to 'The Web', which has lead to such things as GIMPS and this wiki.

As an institution, UCLA has contributed to the discovery of 8 Mersenne primes. This is more than any other university. University of Central Missouri has contributed to the discovery of 4, making it second to UCLA.

## Classic era

Prior to the Internet, 7 Mersenne primes were discovered at UCLA

- In 1952, Raphael Robinson found
**5**Mersenne primes M13 through M17 using UCLA's Standards Western Automatic Computer (SWAC). These were the first ever to be found using a computer. Robinson's Mersenne primes were the first to be found in 75 years (2 in the very first day of the run, no less). And he raised the number of digits of the largest known prime (in general) and Mersenne Prime from 79 and 39 (respectively) to 687. - In 1961, UCLA mathematician Alexander Hurwitz discovered the 19th and 20th Mersenne Primes on the UCLA Computer Center's IBM 7090 mainframe. Each of these numbers had over 1200 digits.

## GIMPS era

Then, more than 45 years later in August of 2008, a Dell Optplex 745 (running a Intel Core 2 Duo E6600 CPU at 2.4GHz) in the UCLA Math department computer lab, found 47th Mersenne prime (M47), the largest known prime at the time, just shy of 13 million digits long. Edson Smith was the team leader for the group that was participating in GIMPS running Prime95 on the PC's in the lab. This is the first prime to be found larger than 10 million (decimal) digits long. This allowed GIMPS to claim one of the EFF prizes.