mersenneforum.org Broken aliquot sequences
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 2020-05-01, 07:45 #34 garambois     Oct 2011 111100002 Posts I think I found a new aliquot sequence with error on FactorDB. It's a sequence that starts with a number < 3,000,000 which is on the blue page. This is the sequence that starts with 1475172, error at index 255. Can anyone confirm ? Code: 253 . 152340387197383120612 = 2^2 * 113 * 337036254861467081 254 . 116614544182067610824 = 2^3 * 17 * 2371 * 4211 * 140297 * 612137 255 . 115052270138377872376 = 2^3 * 457 * 80233 * 278219 * 1409773 256 . 101146402985461010024 = 2^3 * 3727 * 3392353199136739 257 . 88553987910265490776 = 2^3 * 11069248488783186347 should be : Code: 253 : 152340387197383120612 = 2^2 * 113 * 337036254861467081 254 : 116614544182067610824 = 2^3 * 17 * 2371 * 4211 * 140297 * 612137 255 : 115054299854133875896 = 2^3 * 14381787481766734487 256 : 100672512372367141424 = 2^4 * 2503 * 2513796253804613 257 : 94458408032962215712 = 2^5 * 442571 * 6669721357771
 2020-05-01, 19:44 #35 Happy5214     "Alexander" Nov 2008 The Alamo City 11×29 Posts Both the Python mfaliquot library and WolframAlpha support the second version, so it appears the sequence is indeed broken in FactorDB.
 2020-05-07, 08:04 #36 garambois     Oct 2011 24·3·5 Posts I probably found yet another mistake : A new aliquot sequence with error on FactorDB. It's a sequence that starts with a number < 3,000,000 which is on the blue page. This is the sequence that starts with 1866192, error at index 3835. Can anyone confirm ? Code: 3833 . 1857136161022787663609287672 = 2^3 * 19 * 53 * 1072637 * 214917368946554501 3834 . 1877426135009140448634383528 = 2^3 * 947 * 977 * 394747 * 2138897 * 300413621 3835 . 1650071913384946652798107672 = 2^3 * 19 * 6163 * 49009 * 35941092589041083 3836 . 1607243861666293749034420328 = 2^3 * 11 * 18264134791662428966300231 3837 . 1680300400832943464899621432 = 2^3 * 71 * 2958275353579125818485249 should be : Code: 3833 : 1857136161022787663609287672 = 2^3 * 19 * 53 * 1072637 * 214917368946554501 3834 : 1877426135009140448634383528 = 2^3 * 947 * 977 * 394747 * 2138897 * 300413621 3835 : 1650082498696992926527054552 = 2^3 * 631 * 1109 * 65089 * 33131089 * 136682041 3836 : 1451567367500391297153505448 = 2^3 * 137 * 24708664649 * 53601552304837 3837 : 1289987788382339502020263552 = 2^7 * 7 * 405382183 * 3551509104729389
 2020-05-07, 20:15 #37 EdH     "Ed Hall" Dec 2009 Adirondack Mtns 24·3·67 Posts Confirmed! This is what Aliqueit tells me: Code: Verifying index 3835... ERROR: @index 3835: value != sigma - n Corrected lines match yours: Code:  3835 . 1650082498696992926527054552 = 2^3 * 631 * 1109 * 65089 * 33131089 * 136682041 3836 . 1451567367500391297153505448 = 2^3 * 137 * 24708664649 * 53601552304837 3837 . 1289987788382339502020263552 = 2^7 * 7 * 405382183 * 3551509104729389 3838 . 1647037987054673586242766848 = 2^11 * 7 * 321403 * 52293193 * 6835661317
 2020-05-14, 09:21 #38 garambois     Oct 2011 24×3×5 Posts OK, verification of all aliquot sequences starting with numbers less than 3,000,000 is complete. Thanks to Happy5214 and EdH for confirming errors found on factorDB. Can someone please give me the last 80-digit terms of the 3 broken aliquot sequences on FactorDB ? 933564 1475172 1866192 I need these 3 terms to complete my updated C80 database I was talking about here : https://www.mersenneforum.org/showthread.php?t=24423 I hope someone has those three 80 digits terms... If not, I will have to delete these three aliquot sequences from my C80 database. Excuse me, but may I also point out that the two errors reported recently were not reported on the blue page.
 2020-05-14, 13:45 #39 EdH     "Ed Hall" Dec 2009 Adirondack Mtns 321610 Posts I think these are the correct last c80's for the unbroken three sequences: Code: 933564 = 53910798253283852177545053052282940198337166755985147396297057839253859396629560 1475172 = 70632199920744621702989746940578378226575559519111823940659865966774451778707304 1866192 = 97488918894772105620549720764059516378747055783492651624463822352092076013025324 These are not from the broken elf's, but from what should have been the correct elf's later on.
 2020-05-14, 14:46 #40 garambois     Oct 2011 3608 Posts Thank you very much EdH ! This is exactly what I needed. How did you get the data for these three aliquot sequences ? I realize that an aliquot sequence merge is detected when entering data into the FactorDB database. Any merge detected using one of the three broken aliquot sequence on FactorDB will be false...
2020-05-14, 16:27   #41
EdH

"Ed Hall"
Dec 2009

1100100100002 Posts

Quote:
 Originally Posted by garambois Thank you very much EdH ! This is exactly what I needed. How did you get the data for these three aliquot sequences ? I realize that an aliquot sequence merge is detected when entering data into the FactorDB database. Any merge detected using one of the three broken aliquot sequence on FactorDB will be false...
Here are the steps I took for 933564 (which included writing a couple scripts to fix the numbering and search for the last c80):

2. - rename to alq_933564.elf
3. - check 933564 with "./aliqueit 933564 -t"
4. - delete the lines after the last valid line
5. - run "./aliqueit 933564 -q"
6. - take last composite from alq_933564 (1150187197239087798)
7. - query factordb for sequence 1150187197239087798
9. - remove new last line from alq_933564.elf to prevent duplication
10. - splice* the 933564 and 1150187197239087798 elf's together
11. - replace the original alq_933564.elf with the new spliced file
12. - verify the new alq_933564.elf with "./aliqueit 933564 -t"
13. - grab the last c80 in alq_933564.elf

*I wrote a script to renumber the new spliced file as it joined them, because simply concatenating would leave the original indices for the second elf.

splice-elf.sh script:
Code:
#!/bin/bash

count=0
exec <"$1" while read line do period=$(echo expr index "$line" .) echo "${count} ${line:$period-1}" >>new.elf
let count=${count}+1 done exec <"$2"
do
period=$(echo expr index "$line" .)
echo "${count}${line:$period-1}" >>new.elf let count=${count}+1
done

 2020-05-15, 10:33 #42 garambois     Oct 2011 24×3×5 Posts Thank you very much EdH for this method, I hadn't thought of it ! I can reproduce it with my own means...
 2020-05-15, 12:09 #43 EdH     "Ed Hall" Dec 2009 Adirondack Mtns 62208 Posts You're quite welcome. Glad I was able to help.
2020-05-16, 07:02   #44
LaurV
Romulan Interpreter

Jun 2011
Thailand

858310 Posts

Quote:
 Originally Posted by EdH *I wrote a script to renumber the new spliced file as it joined them, because simply concatenating would leave the original indices for the second elf.
Nice job. Used to do all this procedure with the editor, in both pn2 and notepad++ you can mark/delete rectangular blocks (using shift+alt) and auto-number text lines. It is only a couple of cut/paste and takes a minute.

Last fiddled with by LaurV on 2020-05-16 at 07:04

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