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F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 171.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Table of n, a(n) for n=3..8.
V. Meally, Letter to N. J. A. Sloane, Feb 1975
E. M. Palmer and R. W. Robinson, Enumeration under two representations of the wreath product, Acta Math., 131 (1973), 123-143.
Cf. A003224, A003225.
Sequence in context: A123429 A207018 A006841 * A061417 A153921 A189582
Adjacent sequences: A003220 A003221 A003222 * A003224 A003225 A003226
N. J. A. Sloane.