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Old 2021-09-14, 15:47   #12
chris2be8's Avatar
Sep 2009

217410 Posts

Flooding factordb with garbage entries is probably illegal in most countries that have laws about computer misuse. But only Syd could tell where the garbage is coming from or start legal action by complaining to the police. I wish he would.

Of course if someone starts bragging about flooding factordb by all means report them to the police.
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Old 2021-09-15, 13:58   #13
Dr Sardonicus
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Feb 2017

497110 Posts

IMO any submission to factordb of a "composite with no known factors" which is "too small" (fewer than 70 decimal digits, say) should be rejected out of hand. IMO those flooding, or trying to flood the site with such submissions should be summarily executed blocked.
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Old 2021-09-16, 02:06   #14
Romulan Interpreter
LaurV's Avatar
Jun 2011

24·13·47 Posts

Those things are not easy to do.

I am not a fan of Syd either (more specifically, his way to maintain things and his non-communicative person), as I mentioned in some previous posts (the authentication on that site still sucks, and I can login like almost anybody else, which still means nothing, as your work is not credited to you anyhow).

But to be objective, "flooding" of the DB is, most of the times (with only few exceptions of deliberate vandalism or stupidity), accidental. That is because how the DB works, if you look for formulas, it will try to generate the series for you. For example, one user tries "3n^2+69" or other stupidity which is very simple, but pick random constants with a low probability that somebody else tried in the past, and voila!, the DB is filled with over 3000 small composites, because it will try to generate them as high n as you look for, and all of them shatter in smaller pieces. Cutting off those features will be even worse (I use it myself many times, looking for CRUS sequences or aliquots, and it is indeed a VERY useful feature).

So, you would need a kind of very clever algorithm to parse your formulas and know when to fill the DB with all those things and when not. The "wrench" method is way easier to implement: the authentication and crediting the users properly, similar to what PrimeNet and thousands of other sites do (damn, no technical forums around, like stackexchange, etc, would let you post comments to other posts unless your "credit" is high enough, like 50 or so, which is not easy to get!), and allow only "trusted" users (i.e. those who do really work for the DB, like factoring, proving primes, etc) to create more than "n" indexes per "time unit" (n and t to be chosen by the admins). And we are back to my pain, haha, crediting system...

Last fiddled with by LaurV on 2021-09-16 at 02:15
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Old 2021-09-16, 16:00   #15
chris2be8's Avatar
Sep 2009

2×1,087 Posts

There are loads of entries like
It was probably added as just the product of the small bits in brackets, then factordb searched for small factors and found the divisors.

Could something like that be added accidentally?
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Old 2021-09-19, 12:01   #16
Happy5214's Avatar
Nov 2008
The Alamo City

2×379 Posts

We also have the formula "64^63%(2^63-1)*3969", which FactorDB has decided to store as not 1, not 2, but 3 different IDs, despite the formula resolving to a 4 digit number! These are now cluttering the unfactored composites list, since by the way it can't tell that 3^4 * 7^2 is a complete factorization.

Edit: It also displays those composites as 23 digits on the status pages. What?

Edit 2: Any guess who entered those numbers into the database?

Last fiddled with by Happy5214 on 2021-09-19 at 12:18 Reason: Who added them?
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