Row: 5876A934012B (Webern, Chamber Symphony op. 21 - 1928).

There are 479001600 rows and 10395 distinct mapped opposites in base 12.
There are 46080 rows for each mapped opposite in base 12.

The distinct degrees of mapped opposites in base 12 are: 12,10,8,6,4,2.
The corresponding cardinalities of mapped opposites by degree are: 4160,2304,1440,1440,970,81.

The mapped opposite of 5876A934012B is B154329876A0 and its degree is 2.
The number of rows in this subset is 81 * 46080 = 3732480.
Sharing the same mapped opposite, each one of the 12 transpositions of 5876A934012B pertains to the same subset.
The number of rows in this subset without transpositions is 81 * 46080/12 = 311040.