2,1

R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs, SIAM J. Algebraic and Discrete Methods, 1 (1980), 382-404.

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

R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs

Sequence in context: A071404 A074133 A078735 this_sequence A065802 A118028 A099392

Adjacent sequences: A004129 A004130 A004131 this_sequence A004133 A004134 A004135

nonn

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