- Longest Lived: M7
Euclid knew that M7 was prime. It wasn't until 1461 that M13 was shown
to be prime. Of course, they weren't called Mersenne primes in those days.
I wrote this from memory. Corrections welcomed.
- Shortest Lived: M4253
One day in 1961, an IBM 7090 at UCLA was left to run the Lucas-Lehmer test
overnight. The next day, Alex Hurwitz read the printouts and saw that M4253
was the 19th Mersenne prime. Success! A new world record!
Alex finally calmed down and read the rest of the listing only
to see that M4423 was also prime. Another world record! M4253 was King
of the Mountain for less than 15 minutes.
- Longest Compute Time: M756839
19 hours on a Cray-2 in 1992.
- Shortest Compute Time: M110503
11 minutes on the NEC SX-2 in January of 1988.
- Biggest Gap Between Exponents: M127-M521
521 is over 4 times 127. The unfortunate Horace Scudder Uhler spent
years looking for Mersenne primes in that range. He used mechanical
calculators (and probably indentured grad students). He was not on
speaking terms with D.H. Lehmer towards the end of his life.
- Most Successful Searcher: David Slowinski
M44497, M86243, M132049, M216091, M756839, M859433
- Most Prolific Computer: SWAC
M521, M607, M1279, M2203, and M2281
- Most Tantalizing Mersenne Sequence
2^2-1, 2^(2^2-1)-1, 2^(2^(2^2-1)-1, ..., ?
= M2, M7, M127, 2^M127-1 ?
Thanks to Alex Hurwitz.
Do you have an idea for another Mersenne Most?
Don't by shy about it,
send me an email!
back to Luke's Mersenne Page
way back to Luke's Home Page
http://primes.utm.edu/mersenne/LukeMirror/mosts.htm -- Revised: 4 Aug 1996
Page by Luke Welsh