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2020-09-01, 05:31
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#1 |
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Sep 2019
23 Posts |
Smallest composite without known factors "stuck" on (10^79-181)%(10^79-1)/9
The "Smallest composite without known factors" on the status page often points to http://factordb.com/index.php?id=1100000000900935563, but that number is actually prime.
Is it possible to fix that entry so that we can see the real smallest unfactored number? |
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2020-09-01, 09:21
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#2 |
"Oliver"
Sep 2017
Porta Westfalica, DE
3×5×29 Posts |
It thinks that 1551548344191988309623860115843108935500421 is a factor of that number for some reason. Maybe it thinks it is composite because it evaluates the expression to 1111111111111111111111111111111111111111111111111111111111111111111111111110931 and not 1111111111111111111111111111111111111111111111111111111111111111111111111111091?
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2020-09-01, 09:28
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#3 |
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Undefined
"The unspeakable one"
Jun 2006
My evil lair
2×3×1,013 Posts |
There is a duplicate entry:
http://factordb.com/index.php?id=1100000000902314000 |
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2020-09-01, 11:43
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#4 |
"Jeppe"
Jan 2016
Denmark
A616 Posts |
There must be or have been some inconsistence on how the precedence is when the parentheses are not explicit.
If you type (10^79-181)%((10^79-1)/9) you come to the fully factored 79-digit composite number: http://factordb.com/index.php?id=1100000000900937469 If you type ((10^79-181)%(10^79-1))/9 you come to the 79-digit prime: http://factordb.com/index.php?id=1100000000902314000 Both these entries are entirely correct. However, the entry you link: http://factordb.com/index.php?id=1100000000900935563 seems to be a mix-up of the two interpretations. It has evaluated to "C" (composite). But when you click Show digits, you see the expansion for the 79-digit prime. I speculate that one piece of code in factordb sees the expression in one way, and another place sees it in the other way, and we have this mix-up. The schizophrenic entry needs to be removed, and (if not fixed already) the operator precedence convention must be consequent. /JeppeSN |
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