0,2

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

P. J. Cameron, Some treelike objects, Quart. J. Math. Oxford, 38 (1987), 155-183.

Sequence in context: A018317 A059794 A141142 this_sequence A050588 A105282 A018325

Adjacent sequences: A007593 A007594 A007595 this_sequence A007597 A007598 A007599

nonn,nice,easy,more

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