2,2

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

S. K. Das, On the enumeration of finite maximal connected topologies, J. Combin. Theory, B 15 (1973), 184-199.

Adjacent sequences: A003094 A003095 A003096 this_sequence A003098 A003099 A003100

Sequence in context: A111974 A066315 A058499 this_sequence A109220 A018034 A000227

nonn

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