0,2

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

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 180.

Sequence in context: A129707 A133546 A152527 this_sequence A028921 A028922 A066150

Adjacent sequences: A005101 A005102 A005103 this_sequence A005105 A005106 A005107

nonn,hard

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