1,2

J. H. Kwak and J. Lee, J. Graph Th., 23 (1996), 105-109.

V. A. Liskovets, Reductive enumeration under mutually orthogonal group actions, Acta Applic. Math., 52 (1998), 91-120.

R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 5.13(c), pp. 76, 112.

J. H. Kwak and J. Lee, Enumeration of graph coverings and surface branched coverings, Lecture Note Series 1 (2001), Com^2MaC-KOSEF, Korea. See chapter 3.

Cf. A057004-A057013.

Sequence in context: A078961 A049292 A069406 this_sequence A159487 A130661 A049081

Adjacent sequences: A057005 A057006 A057007 this_sequence A057009 A057010 A057011

nonn

N. J. A. Sloane (njas(AT)research.att.com), Sep 09 2000

More terms from Francisco Salinas (franciscodesalinas(AT)hotmail.com), Dec 25 2001