4,2

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

Walsh, T. R. S.; Counting unlabeled three-connected and homeomorphically irreducible two-connected graphs. J. Combin. Theory Ser. B 32 (1982), no. 1, 12-32.

Index entries for sequences related to bricks

Cf. A006292, A006293.

Sequence in context: A137143 A069430 A020564 this_sequence A054678 A036902 A142204

Adjacent sequences: A006288 A006289 A006290 this_sequence A006292 A006293 A006294

nonn

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