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Old 2020-09-01, 11:43   #4
JeppeSN's Avatar
Jan 2016

2428 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:

If you type ((10^79-181)%(10^79-1))/9 you come to the 79-digit prime:

Both these entries are entirely correct.

However, the entry you link:
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.

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