Seeds are actually not formatted at all, they are nothing more or less than a random number. Therefore, as you rightly say, the 05162020 is the only seed that will give you both Crimson and Corruption; there is no random seed that will grant you that.Well, you've asked us to not suggest literally the only seed that is designed to offer both.
Proper map seeds are formatted as [size].[difficulty].[world evil].[identifier]. World evil is a 1 or a 2 depending on corruption, or crimson. Your only hope is a 3 on that evil spot will give you what you want, otherwise you're making yourself the opposite evil talking with the dryad in a graveyard to buy the grass seeds for the other evil.
Oh, they're not? Then the official wiki needs the bit showing them formated as such, complete with screenshot, fixed.Seeds are actually not formatted at all, they are nothing more or less than a random number. Therefore, as you rightly say, the 05162020 is the only seed that will give you both Crimson and Corruption; there is no random seed that will grant you that.
The first three numbers with periods do specify the details you mentioned (though 3 is not a valid option for the world evil). But these three numbers specify world options for convenience purposes; they don't form part of the seed itself. What Kazzymodus was referring to is what you called the identifier, which is indeed random, and no random seed will give you both evils.Oh, they're not? Then the official wiki needs the bit showing them formated as such, complete with screenshot, fixed.