1,4

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. Mullin and P. J. Schellenberg, The enumeration of c-nets via triangulations, J. Combin. Theory, 4 (1968), 259-276.

Sequence in context: A135905 A028498 A001397 this_sequence A088815 A036691 A002866

Adjacent sequences: A001503 A001504 A001505 this_sequence A001507 A001508 A001509

nonn

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