Normal form for a relation where the number of tuples having the same value in a column is the same for all the possible values in that column
How would you populate such a relation? If you required 3 records per id the relation could not exist, as when it is first created this criteria will not be met (until the relation is populated with records).

I think this would have less to do with normal form and more to do with database constraints. Even then, I think it would only allow a MAX of n records with the same id, but not a minimum. Resulting in 0-n records per id.

What problem are you solving? Perhaps some fresh eyes could guide you toward a new approach.