%I #6 May 24 2018 18:10:08
%S 1,1,6,18,73,240,841,2714,8758,27259,83847,252929,754737,2225129,
%T 6505344,18867696,54384446,155892016,444839696,1264336132,3581584336,
%U 10116577962,28505061687,80146304124,224929999040,630259883854,1763574118096,4928881367449
%N Number of monocyclic skeletons with n carbon atoms and a ring size of 9.
%D Camden A. Parks and James B. Hendrickson, Enumeration of monocyclic and bicyclic carbon skeletons, J. Chem. Inf. Comput. Sci., vol. 31, 334-339 (1991).
%H Andrew Howroyd, <a href="/A121156/b121156.txt">Table of n, a(n) for n = 9..200</a>
%Y Column k=9 of A305059.
%K nonn
%O 9,3
%A _Parthasarathy Nambi_, Aug 13 2006
%E Terms a(26) and beyond from _Andrew Howroyd_, May 24 2018