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Off topic discussion • Re: A bit of Raspberry with 192C/384T

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I did not answer earlier because I just completed cado-nfs factorizations for RSA-120/129/130/140/150 and RSA-155 with 192C/384T server. While it was only minutes better for RSA-129, it was more than double as fast with 11:52:54h for RSA-155 (512 bit) than my 16C/32T AMD 7950X PC(!), rightmost column:
https://github.com/Hermann-SW/RSA_numbe ... ring-rsa-x
I updated the table, was able to factor RSA-160 in less than 20h(!), in addition:
https://github.com/Hermann-SW/RSA_numbe ... of-rsa-160

Mathematica is now available on Trixie.

viewtopic.php?p=2344550#p2344550
Good to hear that.

I did next step of investigation of Wolfram student license.
I found detailed instructions from Heidelberg University computing center on the steps for student license.

I hope your class goes well. One of the things I've noticed is that every course requires a lot of work, no matter whether the material is familiar or not.
I can confirm that working on weekly homework is time consuming, but still all is fun.
I updated the lectures I want to take, and converted to English for my personal website:
https://stamm-wilbrandt.de/en/#future

What I learned from translation is, that German "Funktionentheorie" becomes "complex analysis" which seems to indicate that all analysis lectures before deal with ℝ or ℝⁿ, while complex analysis is about ℂ ...

https://stamm-wilbrandt.de/GraphvizFiddle/#_math
HD.math.png

P.S:
In one of the homework excercises we had to prove by induction that

Code:

F(n)^2 + F(n+1)^2 = F(2n+1)
for Fibonacci numbers F(n).

I remembered having seen that formula (Koschy (D)) when I added

Code:

F(2*n) = F(n+1)^2 - F(n-1)^2
to online encyclopedia of integer sequences back in 2015 (search for "Stamm-Wilbrandt"):
https://oeis.org/A000045

So Koshy's formula allows to determine (unique) sum of two squares representation for Fibonacci prime numbers immediately.
Here for largest proven prime Fibonacci number F(201107).

Code:

hermann@7950x:~$ gp -q? F=fibonacci(201107);? #digits(F)42029? A=fibonacci(100553);? B=fibonacci(100554);? F==A^2+B^21?
It can be computed with PARI/GP as well (needs more than 9GB RAM, so not on my 4GB Pi5):

Code:

? s=sqrt(Mod(-1,F));? ##  ***   last result computed in 1min, 6,757 ms.? [M,V]=halfgcd(lift(s),F);[C,D]=[V[2],M[2, 1]];? ##  ***   last result computed in 3 ms.? F==C^2+D^21? 

Statistics: Posted by HermannSW — Mon Nov 03, 2025 12:13 am



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