1,2

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

R. C. Read, Some Enumeration Problems in Graph Theory. Ph.D. Dissertation, Department of Mathematics, Univ. London, 1958.

Sequence in context: A051770 A032181 A081073 this_sequence A114053 A134823 A000880

Adjacent sequences: A002828 A002829 A002830 this_sequence A002832 A002833 A002834

nonn

N. J. A. Sloane (njas(AT)research.att.com).