A121942 Number of digraphs of hydrogen bonded water clusters.

1, 5, 22, 161, 1406, 14241, 164461, 2115335, 29903139, 460066726, 7644586673, 136336779596, 2596190669230, 52552267768902, 1126421027176730

Offset: 2

Author

Parthasarathy Nambi, Sep 03 2006

Keywords

• nonn

Examples

			If n=5 then the number of digraphs of hydrogen bonded water clusters is 161.
		

References

• T. Miyake and M. Aida, "Enumeration of topology-distinct structures of hydrogen bonded water clusters", Chem. Phys. Lett., vol. 363 (2002) pp. 106-110. See Table 1 column 3 on page 109.

Links

• B. Brinkmann, Generating water clusters and other directed graphs, J. Math. Chem. 46 (4) (2009) 1112-1121, Table 1.

Extensions

More terms copied from Brinkmann's table. - R. J. Mathar, Mar 27 2019