Number of tone-rows in n-tone music.

Terms

a(0) =1a(1) =3a(2) =8a(3) =38a(4) =192a(5) =1320a(6) =10176a(7) =91296a(8) =908160a(9) =9985920a(10) =119761920a(11) =1556847360a(12) =21794734080a(13) =326920043520