phyzguy said:
Mathematica, or Wolfram alpha (
http://www.wolframalpha.com) will calculate primes, but I doubt that they will go up to 8E20 in any reasonable time. It can calculate primes up to ~1E12 in a few seconds, but if I'm not mistaken calculating primes is approximately an O(N) algorithm, so it will take years to go up to ~1E20. What are you trying to do? Calculate all of the primes up to 8E20? Where would you store them?
Luckily I didn't need all the primes just something that can verify them up to that value but preferably much higher. I found this site,
http://www.alpertron.com.ar/ECM.HTM
So far it has been able to verify the primes I generated up to
125,024,575,647,509,552,016,558,656,041 and 125,024,575,647,509,552,016,558,656,167
Not bad at all. Unfortunately my calculator/pen and paper method do not allow me to go any further. Guess that will need upgraded next.
***EDIT*** found a better calculator.
New personal record for generating primes using calculator/pen and paper method is now at,
52,098,944,879,727,879,738,571,834,212,718,601,969,472,403,507,608,638,174,209,127
and,
52,098,944,879,727,879,738,571,834,212,718,601,969,472,403,507,608,638,174,208,761
and there you have it. Sorry for over-posting but these primes are a lot of fun!
****EDIT**** Calculator/pen and paper method,
Okay, one more time,
3,791,737,052,794,739,934,469,477,610,338,330,426,610,616,534,498,673,313,167,532,771,648,137,234,488,985,048,534,111,985,849,083,656,689
and,
3,791,737,052,794,739,934,469,477,610,338,330,426,610,616,534,498,673,313,167,532,771,648,137,234,488,985,048,534,111,985,849,083,657,093
Those primes are both well over a googel! Woo Hoo!
Not bad for pen, paper and calculator :)
