0,3

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

H. Brown, R. B\"{u}low, J. Neub\"{u}ser, H. Wondratschek and H. Zassenhaus, Crystallographic Groups of Four-Dimensional Space. Wiley, NY, 1978, p. 52.

Sequence in context: A061595 A062940 A075813 this_sequence A107952 A123046 A087784

Adjacent sequences: A004029 A004030 A004031 this_sequence A004033 A004034 A004035

hard,nonn,nice

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