Row: 074A268B1359 (the harmonic row, i.e. the natural suite of harmonics supposed 
by shoenbergian theory to be the origin of tonal music).

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 074A268B1359 is 91B7825346A0 and its degree is 6.
The number of rows in this subset is 1440 * 46080 = 66355200.
Sharing the same mapped opposite, each one of the 12 transpositions of 074A268B1359 pertains to the same subset.
The number of rows in this subset without transpositions is 1440 * 46080/12 = 5529600.