Unidentified subject!

[web23.web138@web23.web138.web28.dogado.de]

Sorry, problems with my webmailer, sending this with mail command from my hosted server.

On 2026-03-07 16:00, Karim Belabas wrote:
> * hermann@stamm-wilbrandt.de [2026-03-07 14:48]:
> [...]
>> So I cannot read it on my fast AMD 7950X PC with 32GB RAM. Anyway
>> phantastic!
>>
>> ? b=read("carm10e24.bin");
> [...]
> 
> A trick (which may or may not help here) to reduce memory use by a
> factor 2 or so. The above saves the result twice in memory: in b as
> explicitly intended ... and in gp's history.
> 
>   ? b=read("carm10e24.bin"); 0  \\ for instance
> 
> only saves 0 in history, not the full b.
> 
> Cheers,
> 
>     K.B.
>
https://stamm-wilbrandt.de/cgi-bin/echo-e.to.braille.pl?i=Thanks+-+you+saved+my+day%21

$ echo -e 'Thanks - you saved my day!' | pbmtext -builtin fixed | pnmcrop | pbmtobraille
⡖⢲⠒⡎⡇⣀⠀⢀⣀⡀⢀⢀⣀⠀⢹⠀⣀⠀⢀⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⢀⣀⠀⣀⡀⢀⡀⢀⡀⠀⠀⠀⠀⢀⣀⠀⢀⣀⡀⢀⣀⢀⣀⠀⣀⡀⠀⢀⣈⡇⠀⠀⠀⢀⣀⢀⠀⣀⡀⣀⡀⠀⠀⠀⠀⣀⣹⠀⣀⣀⠀⣀⡀⣀⡀⠀⡇
⠀⢸⠀⠀⡏⠀⡇⢠⠒⢺⠀⡏⠀⡇⢸⠪⡀⠀⡑⠒⡅⠀⠀⠀⠀⠒⠒⠂⠀⠀⠀⠀⢣⣠⠃⢸⠀⢸⠀⡇⠀⡇⠀⠀⠀⠀⡑⠒⡅⢠⠒⢺⠀⢣⣠⠃⢸⠒⢚⠀⡇⠀⡇⠀⠀⠀⠀⡇⡇⡇⠘⣄⡜⠀⠀⠀⠀⢸⠀⢸⠀⡔⠒⡇⠘⣄⡜⠀⠀⠇
⠈⠉⠉⠈⠉⠈⠉⠀⠉⠁⠉⠉⠀⠉⠉⠀⠈⠁⠈⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⠇⠀⠀⠉⠁⠀⠈⠉⠈⠀⠀⠀⠀⠈⠉⠀⠀⠉⠁⠁⠀⠁⠀⠀⠉⠁⠀⠈⠉⠈⠀⠀⠀⠈⠁⠁⠉⢀⡸⠀⠀⠀⠀⠀⠀⠉⠁⠁⠈⠉⠈⢀⡸⠀⠀⠀⠁
$ 


Your "history" trick did make the 308 million Carmichael numbers fit into my fast AMD 7950X CPU PC.    
And that has fast DDR5 RAM and SSDs as storage, and not raid HDDs as my 2-socket server.

I started gp, did the read() and looked for gp pid in top.    
Then I queried resident RAM after read() on command line:

hermann@7950x:~$ ps -o pid,user,vsz,rss,comm,args 4856
    PID USER        VSZ   RSS COMMAND         COMMAND
   4856 hermann  42311356 24028804 gp         gp -q
hermann@7950x:~$

Not 38/2 GB resident RAM but 23GB.    
Now fits easily into 32GB RAM of my PC, and read time now is only 18 seconds!

hermann@7950x:~$ gp -q
? #
   timer = 1 (on)
? b=read("carm10e24.bin");0
cpu time = 3,751 ms, real time = 17,627 ms.
0
? #b
308279939
? b[#b]
999999999855878641139521
? d=10^3;C=0;foreach(b,c,if(c>=d,print1(C",");d=d*10);C+=1);print(C)
1,7,16,43,105,255,646,1547,3605,8241,19279,44706,105212,246683,585355,1401644,3381806,8220777,20138200,49679870,123381982,308279939
cpu time = 56,718 ms, real time = 56,722 ms.
? 

The last loop verifies the 10^n Carmichael number counts of https://oeis.org/A055553 .


The server I did download the 184GB file from was slow, so it took 4:58h(!) to download.

For people interested in Carmichael numbers    
https://en.wikipedia.org/wiki/Carmichael_number    
up to 10^24 I did upload the binary file to my personal website.   
 
Depending on your download speed (I have 1Gbps cable internet) you can get it in 2min!

hermann@7950x:~/Downloads$ wget https://stamm-wilbrandt.de/carm10e24.bin
...
carm10e24.bin       100%[===================>]  11,45G  83,7MB/s    in 1m 47s  

2026-03-07 16:13:29 (109 MB/s) - ‘carm10e24.bin’ saved [12296962769/12296962769]

hermann@7950x:~/Downloads$ diff carm10e24.bin ~/carm10e24.bin 
hermann@7950x:~/Downloads$ time sha256sum carm10e24.bin 
964abcc780b9786ae9f18d75a688cfc83f2bf74fb592ead9f58fd94bf6441946  carm10e24.bin

real	0m5,355s
user	0m4,521s
sys	0m0,834s
hermann@7950x:~/Downloads$


Regards,

Hermann.