3,2

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 171.

E. M. Palmer and R. W. Robinson, Enumeration under two representations of the wreath product, Acta Math., 131 (1973), 123-143.

Cf. A003224, A003223.

Adjacent sequences: A003222 A003223 A003224 this_sequence A003226 A003227 A003228

Sequence in context: A032078 A067210 A018654 this_sequence A007663 A018695 A078221

nonn,easy,more

njas