Number of unlabeled mobiles with cycles of length at least 3.

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =1a(5) =2a(6) =3a(7) =6a(8) =12a(9) =25a(10) =53a(11) =114a(12) =257a(13) =567a(14) =1294a(15) =2944a(16) =6790a(17) =15693a(18) =36598a(19) =85578a(20) =201299a(21) =474975a(22) =1125349a(23) =2674160a(24) =6374879a(25) =15236478a(26) =36510886a(27) =87688909a(28) =211061972a(29) =509015536