0,3

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 157.

E. C. Pervin, personal communication.

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

Sequence in context: A115496 A098237 A068856 this_sequence A031939 A134075 A002617

Adjacent sequences: A006914 A006915 A006916 this_sequence A006918 A006919 A006920

nonn,more

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