A121160 Number of spiro bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).
1, 1, 6, 12, 43, 106, 322, 864, 2483, 6829, 19226, 53293, 148866, 413501, 1151506, 3200184, 8901478, 24742852, 68800520, 191275736, 531888416
Offset: 5
Links
- Camden A. Parks and James B. Hendrickson, Enumeration of monocyclic and bicyclic carbon skeletons, J. Chem. Inf. Comput. Sci., vol. 31, 334-339 (1991).
Extensions
More terms from N. J. A. Sloane, Aug 27 2006