A121159 Number of spiro bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).

1, 4, 16, 53, 175, 547, 1692, 5127, 15408, 45831, 135500, 398186, 1165005, 3394880, 9861048, 28561403, 82525483, 237941827, 684778523, 1967510639

Offset: 6

Author

Parthasarathy Nambi, Aug 13 2006

Keywords

• nonn

References

• Camden A. Parks and James B. Hendrickson, Enumeration of monocyclic and bicyclic carbon skeletons, J. Chem. Inf. Comput. Sci., vol. 31, 334-339 (1991).