I've been crunching large numbers that involve 2 for a long time. They're mainly primality tests for k*[b]2[/b]^n-1, k*[b]2[/b]^n+1, and [b]2[/b]^p-1.

So I thought, why not calculate something else that also involves 2? But instead of crunching such huge numbers, why not work on something much smaller that has the bulk of its digits on the other side of the decimal point?

Well, here it is. I calculated the natural logarithm of 2 (which is 0.69314718...) to 6x10^11 decimal digits, setting a new world record!
[url]http://www.numberworld.org/y-cruncher/[/url]

Surprisingly, running this calculation didn't cause much of a conflict with prime hunting. That's because the bottleneck for calculating constants to billions of decimal places is not CPU speed (like it is for prime hunting), but hard disk input/output. As a side note, the program I used to calculate ln (2) is also the same program used to calculate pi to a record 22,459,157,718,361 decimal digits:
[url]https://fivethirtyeight.com/features/even-after-22-trillion-digits-were-still-no-closer-to-the-end-of-pi/[/url]

The motivation for calculating constants and for finding large primes is remarkably similar. They're both used for bragging rights and for testing hardware, but the deeper appeal is to satisfy human curiosity and the opportunity to add to the sum total of human knowledge without needing special talents, a college degree, or a large personal time commitment. We know that pi=3.14159...9237..., but what comes after that 7? Similarly, what is the next Mersenne prime after M51? And how is their distribution? Are Mersenne primes clustered together, and is ln (2) a normal number?

We may never know the answers, but the journey is just as fun as the destination.

I just turned over the 1000th factor in GPU72 records. An amusing detail is 666 LL factors. :smile:

I'm getting a Nintendo Wii for Christmas, courtesy of my parents!

Made it to another milestone on my bicycle, and was going to take a picture of the nice big round number on the odometer. But then decided I should really take the picture when it turned over the first prime after the big round number. And then noticed that the first prime was a twin prime, so I took the picture of the number in between the twin primes. (It looks like a night time shot because this time of year, my commute home is in the dark).

Norm

That's a lot of calories!

:max:

We clocked 82,464 miles for 2018 but we cheated and used a motorsickle.

:mike:

[QUOTE=Xyzzy;504360]

We clocked 82,464 miles for 2018 but we cheated and used a motorsickle.

:mike:[/QUOTE]

Good Grief- that's a lot miles in one year. Hopefully those are not primarily commuter miles, and are therefore great scenery miles. Congrats!

Norm

[QUOTE=Spherical Cow;504482]Good Grief- that's a lot miles in one year. Hopefully those are not primarily commuter miles, and are therefore great scenery miles. Congrats!

Norm[/QUOTE]
You can follow him here:
[url]http://www.mob-rule.com/user-gifs/USA/xyzzy.gif[/url]

[QUOTE=Xyzzy;504360]
We clocked 82,464 miles for 2018 but we cheated and used a motorsickle.

:mike:[/QUOTE]
Congrats! I've only gone 20,018 miles in 2018.

Mileage log:
[code]
Jan 18
1 - 43 miles 17 - 26 miles
2 - 29 miles 18 - 35 miles
3 - 32 miles 19 - 101 miles
4 - 56 miles 20 - 64 miles
5 - 63 miles 21 - 75 miles
6 - 28 miles 22 - 29 miles
7 - 22 miles 23 - 30 miles
8 - 28 miles 24 - 26 miles
9 - 29 miles 25 - 26 miles
10 - 29 miles 26 - 39 miles
11 - 25 miles 27 - 65 miles
12 - 38 miles 28 - 19 miles
13 - 285 miles 29 - 31 miles
14 - 7 miles 30 - 25 miles
15 - 37 miles 31 - 23 miles
16 - 35 miles
Total - 1400 miles

Feb 18
1 - 25 miles 15 - 25 miles
2 - 280 miles 16 - 64 miles
3 - 42 miles 17 - 25 miles
4 - 17 miles 18 - 4 miles
5 - 25 miles 19 - 72 miles
6 - 29 miles 20 - 26 miles
7 - 40 miles 21 - 30 miles
8 - 36 miles 22 - 30 miles
9 - 35 miles 23 - 77 miles
10 - 15 miles 24 - 41 miles
11 - 73 miles 25 - 96 miles
12 - 31 miles 26 - 28 miles
13 - 37 miles 27 - 31 miles
14 - 26 miles 28 - 30 miles
Total - 1290 miles

March 18
1 - 29 miles 17 - 70 miles
2 - 72 miles 18 - 64 miles
3 - 0 miles 19 - 28 miles
4 - 4 miles 20 - 36 miles
5 - 30 miles 21 - 28 miles
6 - 27 miles 22 - 29 miles
7 - 28 miles 23 - 44 miles
8 - 31 miles 24 - 0 miles
9 - 111 miles 25 - 74 miles
10 - 182 miles 26 - 28 miles
11 - 64 miles 27 - 28 miles
12 - 29 miles 28 - 25 miles
13 - 30 miles 29 - 46 miles
14 - 30 miles 30 - 18 miles
15 - 215 miles 31 - 50 miles
16 - 60 miles
Total - 1510 miles

April 18
1 - 1 mile
2 - 29 miles
3 - 25 miles
4 - 30 miles
5 - 30 miles
6 - 52 miles
7 - 32 miles
8 - 0 miles
9 - 41 miles
10 - 29 miles
11 - 28 miles
12 - 30 miles
13-23 - 683 miles
24 - 20 miles
25-26 - 55 miles
27-30 - 1315 miles
Total - 2400 miles

May 18
1 - 28 miles 17 - 75 miles
2 - 29 miles 18 - 30 miles
3 - 22 miles 19 - 2 miles
4 - 54 miles 20 - 64 miles
5 - 0 miles 21 - 28 miles
6 - 37 miles 22 - 25 miles
7 - 25 miles 23 - 28 miles
8 - 35 miles 24 - 46 miles
9 - 28 miles 25 - 11 miles
10 - 36 miles 26 - 252 miles
11 - 17 miles 27 - 5 miles
12 - 0 miles 28 - 0 miles
13 - 63 miles 29 - 30 miles
14 - 28 miles 30 - 27 miles
15 - 30 miles 31 - 35 miles
16 - 260 miles
Total - 1350 miles

June 18
1 - 76 miles 16 - 71 miles
2 - 0 miles 17 - 4 miles
3 - 3 miles 18 - 30 miles
4 - 29 miles 19 - 24 miles
5 - 27 miles 20 - 28 miles
6 - 30 miles 21 - 53 miles
7 - 45 miles 22 - 2 miles
8 - 5 miles 23 - 3 miles
9 - 65 miles 24 - 68 miles
10 - 93 miles 25 - 28 miles
11 - 27 miles 26 - 29 miles
12 - 28 miles 27 - 30 miles
13 - 26 miles 28 - 0 miles
14 - 27 miles 29 - 47 miles
15 - 48 miles 30 - 154 miles
Total - 1100 miles

July 18
1 - 2 miles 17 - 30 miles
2 - 44 miles 18 - 26 miles
3 - 35 miles 19 - 47 miles
4 - 83 miles 20 - 0 miles
5 - 32 miles 21 - 1 mile
6 - 114 miles 22 - 61 miles
7 - 0 miles 23 - 31 miles
8 - 64 miles 24 - 30 miles
9 - 26 miles 25 - 27 miles
10 - 29 miles 26 - 25 miles
11 - 25 miles 27 - 54 miles
12 - 25 miles 28 - 61 miles
13 - 51 miles 29 - 43 miles
14 - 49 miles 30 - 29 miles
15 - 3 miles 31 - 27 miles
16 - 26 miles
Total - 1100 miles

Aug 18
1 - 25 miles 17 - 45 miles
2 - 25 miles 18 - 47 miles
3-5 - 950 miles 19 - 0 miles
6 - 30 miles 20 - 25 miles
7 - 25 miles 21 - 23 miles
8 - 27 miles 22 - 29 miles
9 - 31 miles 23 - 25 miles
10 - 49 miles 24 - 49 miles
11 - 37 miles 25 - 46 miles
12 - 46 miles 26 - 1 mile
13 - 31 miles 27 - 27 miles
14 - 30 miles 28 - 25 miles
15 - 24 miles 29 - 42 miles
16 - 45 miles 30-31 - 641 miles
Total - 2400 miles

Sept 18
1 - 200 miles 18 - 27 miles
2 - 200 miles 19 - 24 miles
3 - 983 miles 20 - 31 miles
4 - 26 miles 21 - 44 miles
5 - 24 miles 22 - 36 miles
6 - 29 miles 23-24 - 25 miles
7 - 47 miles 25 - 24 miles
8 - 80 miles 26 - 26 miles
9 - 26 miles 27 - 46 miles
10 - 29 miles 28 - 5 miles
11 - 24 miles 29 - 17 miles
12 - 26 miles 30 - 5 miles
13 - 53 miles
14 - 94 miles
15-17 - 24 miles
Total - 2175 miles

Oct 18
1 - 27 miles 17 - 25 miles
2 - 25 miles 18 - 27 miles
3 - 27 miles 19 - 46 miles
4 - 27 miles 20 - 60 miles
5 - 50 miles 21-23 - 25 miles
6 - 17 miles 24 - 27 miles
7 - 82 miles 25 - 24 miles
8 - 28 miles 26 - 448 miles
9 - 26 miles 27 - 38 miles
10 - 24 miles 28-29 - 24 miles
11-14 - 1400 miles 30 - 25 miles
15 - 25 miles 31 - 24 miles
16 - 24 miles
Total - 2575 miles

Nov 18
1 - 24 miles 17 - 73 miles
2 - 49 miles 18 - 176 miles
3-5 - 30 miles 19 - 49 miles
6 - 25 miles 20 - 30 miles
7 - 24 miles 21 - 49 miles
8 - 52 miles 22 - 20 miles
9 - 17 miles 23 - 46 miles
10 - 171 miles 24 - 41 miles
11 - 77 miles 25 - 42 miles
12-13 - 26 miles 26 - 30 miles
14 - 25 miles 27 - 24 miles
15 - 26 miles 28 - 26 miles
16 - 48 miles 29 - 26 miles
30 - 49 miles
Total - 1275 miles

Dec 18
1 - 50 miles 18 - 27 miles
2 - 46 miles 19 - 26 miles
3 - 25 miles 20 - 46 miles
4 - 27 miles 21 - 17 miles
5 - 27 miles 22 - 46 miles
6-11 - 522 miles 23 - 59 miles
12 - 25 miles 24 - 28 miles
13 - 31 miles 25 - 37 miles
14 - 45 miles 26 - 30 miles
15 - 46 miles 27 - 30 miles
16 - 45 miles 28 - 51 miles
17 - 30 miles 29 - 73 miles
30 - 25 miles
31 - 29 miles
Total - 1443 miles
[/code]

[QUOTE=Uncwilly;504530]You can follow him here:
[url]http://www.mob-rule.com/user-gifs/USA/xyzzy.gif[/url][/QUOTE]

That's incredible- I'm going to check back every few days to see what color 2019 is.

Norm

I have an account there too. 2017 was a good year for me. Hurricane Harvey messed up some of my plans though.

My new PC is ready!
 

Waited for it since 2013... :smile:

Finally a no-compromise rig on my desktop!