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Search: Posts Made By: paulunderwood
Forum: Riesel Prime Search 2021-10-18, 22:55
Replies: 280
Views: 49,334
Posted By paulunderwood
Two birds with one stone

Congrats tp Ryan and Serge for the record Near-rep Digit / Palindrome prime 10^1888529 - 10^944264 - 1 (https://primes.utm.edu/primes/page.php?id=132851)
Forum: Riesel Prime Search 2021-10-18, 20:18
Replies: 438
Views: 83,639
Posted By paulunderwood
k=23

We would like to reserve k=23 from n=5,000,000 under "Underwood et al" :smile:
Forum: Math 2021-10-18, 14:11
Replies: 5
Views: 113
Posted By paulunderwood
Err, Nick, n^2^p would be n^2 mod Mp. Usually we...

Err, Nick, n^2^p would be n^2 mod Mp. Usually we use "a" not "n" and n=2^p-1.
Forum: Software 2021-10-18, 13:59
Replies: 508
Views: 99,710
Posted By paulunderwood
Thanks head -n1 Downloads/helper.ini | wc ...

Thanks

head -n1 Downloads/helper.ini | wc
1 1 21

Whereas 520461*2^55931+1 has 16+2 characters if Windows. Did you copy this number from the net?


cat -A...
Forum: Software 2021-10-18, 13:44
Replies: 508
Views: 99,710
Posted By paulunderwood
Please attach your helper file for inspection....

Please attach your helper file for inspection. :smile:

Use the forum's paperclip.
Forum: Software 2021-10-18, 11:08
Replies: 508
Views: 99,710
Posted By paulunderwood
If you have copy and pasted a number into the...

If you have copy and pasted a number into the helper file, especially from the web, it might have non-printable characters in it. Please attach the file "xyz".
Forum: Software 2021-10-18, 10:57
Replies: 508
Views: 99,710
Posted By paulunderwood
One thing to try: rename "xyz" to "helper" and...

One thing to try: rename "xyz" to "helper" and run with -hhelper
Forum: Software 2021-10-18, 10:39
Replies: 508
Views: 99,710
Posted By paulunderwood
Does xyz contain the word "numbers"?

Does xyz contain the word "numbers"?
Forum: PrimeNet 2021-10-16, 22:27
Replies: 108
Views: 26,129
Posted By paulunderwood
Work being done on my Odrod N2 running mlucas P-1...

Work being done on my Odrod N2 running mlucas P-1 has been poached - c105M. It is now switched off until next summer when it will be used for "small projects". The cost of electricity in the UK now...
Forum: Riesel Prime Search 2021-10-16, 17:54
Replies: 280
Views: 49,334
Posted By paulunderwood
Some numbers require proof attempts at increasing...

Some numbers require proof attempts at increasing sizes of FFT.
Forum: Programming 2021-10-15, 19:39
Replies: 41
Views: 1,089
Posted By paulunderwood
For lengthy numbers you might find this is better...

For lengthy numbers you might find this is better as there is no truncation:


ans=$(echo "print($d*$m)" | gp -q -f)
Forum: Miscellaneous Math 2021-10-14, 22:03
Replies: 2
Views: 120
Posted By paulunderwood
Semi-primes are being stubborn, but when I feed...

Semi-primes are being stubborn, but when I feed in Carmichael numbers counterexamples abound such as [n,a]=[19384289, 8494896]

This is yet another test that shows that X Frobenius tests with X...
Forum: Miscellaneous Math 2021-10-14, 01:56
Replies: 2
Views: 120
Posted By paulunderwood
I can save a few Selfridges by using the weaker...

I can save a few Selfridges by using the weaker form of Fermat's Little Theorem:

{
tst(n,a)=kronecker(a^2-4,n)==-1&&
gcd(a+4,n)==1&&
Mod(a-1,n)^n==a-1&&
Mod(a,n)^n==a&&
Mod(a+1,n)^n==a+1&&...
Forum: Hardware 2021-10-13, 20:21
Replies: 167
Views: 34,998
Posted By paulunderwood
https://thepihut.com/products/argon-one-m-2-raspbe...

https://thepihut.com/products/argon-one-m-2-raspberry-pi-4-case

Boot a pi from an M2 drive + 2 full size HDMI sockets
Forum: Miscellaneous Math 2021-10-13, 19:13
Replies: 2
Views: 120
Posted By paulunderwood
Talking Single Parameter Frobenius test -- 1+1+1+1+2 Selfridges

{
tst(n,a)=kronecker(a^2-4,n)==-1&&
gcd((a^3-a)*(a+4),n)==1&&
Mod(a-1,n)^(n-1)==1&&
Mod(a,n)^(n-1)==1&&
Mod(a+1,n)^(n-1)==1&&
Mod(a+4,n)^(n-1)==1&&
Mod(Mod(x+2,n),x^2-a*x+1)^(n+1)==2*a+5;}
...
Forum: Forum Feedback 2021-10-13, 14:34
Replies: 8
Views: 305
Posted By paulunderwood
I use hightlight then ctrl+shift+c to copy from a...

I use hightlight then ctrl+shift+c to copy from a terminal. Finally pasting with ctrl+v. To paste into a terminal use ctrl+shift+v. HTH :smile:
Forum: Riesel Prime Search 2021-10-08, 23:21
Replies: 706
Views: 76,789
Posted By paulunderwood
Here is another found with the Propper treatment:...

Here is another found with the Propper treatment:

https://primes.utm.edu/primes/page.php?id=132808 (1,935,350 digits)
Forum: Programming 2021-10-07, 02:16
Replies: 10
Views: 426
Posted By paulunderwood
I don't understand how it loses "n:". The first...

I don't understand how it loses "n:". The first line must be n and its value and not an empty line. It could be a better script, dropping "j".
Forum: Programming 2021-10-07, 01:18
Replies: 10
Views: 426
Posted By paulunderwood
#!/bin/bash readarray lines < $1 echo...

#!/bin/bash

readarray lines < $1
echo ${lines[0]}
i=1
j=${#lines[@]}
while ! [[ ${lines[$i]} =~ "skew" ]]; do
i=$(expr $i + 1)
echo ${lines[$(expr $j - $i )]}
done
Forum: Hardware 2021-10-06, 16:12
Replies: 22
Views: 4,301
Posted By paulunderwood
FWIW (not much) I implemented a base 3 Fermat PRP...

FWIW (not much) I implemented a base 3 Fermat PRP multi-limb test on my 32 bit Longan Nano. With a 16 bit model, a mult fits in in 32 bits with room for two 16 bit additions without overflow. I do...
Forum: Miscellaneous Math 2021-10-06, 15:57
Replies: 13
Views: 685
Posted By paulunderwood
David Broadhurst gave me a file (attached to this...

David Broadhurst gave me a file (attached to this message) of 100 small frauds that fool tst2, which took 42 seconds to produce.

He also found this 111 digit counterexample:


{[n,a,t,t2]=[...
Forum: Marin's Mersenne-aries 2021-10-06, 13:50
Replies: 56
Views: 1,838
Posted By paulunderwood
Someone should tell Prof. Chris Caldwell about...

Someone should tell Prof. Chris Caldwell about this so he can update his site/database.
Forum: Hardware 2021-10-06, 11:12
Replies: 22
Views: 4,301
Posted By paulunderwood
Not all the registers are general purpose -- some...

Not all the registers are general purpose -- some seem to be for I/O.

I like the small set of registers and instructions. They are easy to remember and therefore to program. Oh what fun! Takes me...
Forum: Programming 2021-10-05, 19:25
Replies: 10
Views: 426
Posted By paulunderwood
#!/bin/bash while read line; do ...

#!/bin/bash

while read line; do
larray=($line)
echo "n: input_number"
echo "c5: ${larray[0]}"
echo "c4: ${larray[1]}"
echo "c3: ${larray[2]}"
echo "c2: ${larray[3]}"...
Forum: Programming 2021-10-05, 08:00
Replies: 41
Views: 1,089
Posted By paulunderwood
a="31363920 948583258055568...

a="31363920 948583258055568 -21094061301960794201597 -101781123694367174730692456309"
echo "$a" > testcase
echo "22$a" >> testcase
c="31363920"
m="3"

printf "\nYAFU says $c*$m is "...
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