If you distribute a number that represents something you're not allowed to distribute, without announcing this connection, you're not really making that secret information available to anyone. There's no loophole there.
You need to somehow include information on how to use the number, which is arguably easier to pull off, but still doesn't make it legal, just harder to find out.
How about if we first standardize a universal, generic encoding scheme which produces numbers? Then if you saw a random number somewhere, you'd know to simply try decoding it with this scheme to see whether it succeeds.
I didn't mean that a mere dissemination of numbers is illegal; rather, RIAA will try to make illegal and will penalize (not yet illegal) dissemination for any means possible exactly because of that. This has a huge implication both for who don't want get in trouble and for who want do the illegal thing.
You need to somehow include information on how to use the number, which is arguably easier to pull off, but still doesn't make it legal, just harder to find out.