13 41 | CERN's Unprecedented 13 TeV Experiment, May 21, 2015

http://home.web.cern.ch/about/updates/2015/05/first-images-collisions-13-tev

41 is the 13th Prime Number.  This test, at 13 TeV, happened on a date with '41' numerology, May 21, 2015.

• 5/21/15 = 5+21+15 = 41
• 41, the 13th Prime Number