Number of set partitions up to rotations and reflections.

Terms

a(0) =1a(1) =2a(2) =3a(3) =7a(4) =12a(5) =37a(6) =93a(7) =354a(8) =1350a(9) =6351a(10) =31950a(11) =179307a(12) =1071265a(13) =6845581a(14) =46162583a(15) =327731950a(16) =2437753740a(17) =18948599220a(18) =153498350745