Number of monocyclic skeletons with n carbon atoms and a ring size of 9.

Terms

a(0) =1a(1) =1a(2) =6a(3) =18a(4) =73a(5) =240a(6) =841a(7) =2714a(8) =8758a(9) =27259a(10) =83847a(11) =252929a(12) =754737a(13) =2225129a(14) =6505344a(15) =18867696a(16) =54384446a(17) =155892016a(18) =444839696a(19) =1264336132a(20) =3581584336a(21) =10116577962a(22) =28505061687a(23) =80146304124a(24) =224929999040a(25) =630259883854