A160871 Column 6 of array in A057004.

1, 63, 7987, 7987616, 24875000437, 193466859054994

Offset: 1

Author

N. J. A. Sloane, Nov 15 2009

Keywords

• nonn

References

• J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161.